Tails was down in his workshop, working on his latest invention. "At last! I've finished!" He said, lifting his welding shield. He wiped the seat off of his brow and walked over to get a rag to clean himself up.

Tails had just invented a genetic transformation machine. By using particles from a chaos emerald, DNA and Protein synthesis could be altered, along with brain wave manipulation. The only problem? Because of the Chaos emerald's instability, the alterations that took place were not COMPLETELY under Tail's control

"I guess the only question now is who to test it on." Tails said to himself, "If I use it on myself, there's no chance of anyone else getting in danger, but there won't be anyone to help if something goes wrong."

Who does Tails test his machine on?

*

Then Tails heard a familiar voice...

"Oy! G'day Tails ya' bloke! How ya' been, mate!"

It was Marine the Raccoon. An inventor in her own right, she no doubt would understand Tails's need to test his new machine.

"Hey Marine, I'm doing good."

"Happy as Larry, eh mate?"

"R-right...say, would you help me test this machine here?" Tails said, gesturing at the device.

"Crikey! You built that big 'ol thing there? Good on ya'! Sure I'll help ya' out, mate!"

...and with that, Marine stepped into the machine.

Now then, what to change on her...

*

"Okay! Marine, are you ready?" asked Tails. "Go ahead Tails you big bloke, show me what this machine can do." said Marine giving the fox boy a wink and smile, Tails calculated for moment before pressing the right buttons on his computer, giving him multiple options such as transforming Marine into anything or anyone else, inflation or growth and shrink, etc. etc. etc. Then he also found the breast expansion option, he could actually have Marine grow a pair of lovely tits on her chest, Tails had a secret smile on his face, the thought of making Marine the Raccoon girl so sexy he was intrigued. "Here We Go." he exclaimed happily when he chose the breast expansion option and entered the command and the pushed the button. The machine began humming from the inside and Marine feeling a little impatient started to get grumpy as couldn't wait any longer. "Tails what's taking so long?" she cried, "Just give it a minute." said Tails. Suddenly, there was a flash of flickering lights inside the machine surrounding Marine, they continued to flash in a variety of colors and then all was white. Tails opened the front door of the machine and checked if Marine was alright and then a figure stepped out of the machine, it was Marine. Tails checked on her and made sure there were no horrible side effects, "Marine are you okay?" Tails asked in concern feeling guilty at the thought of nearly killing her by experimenting on her, Marine felt a little dizzy but she shook her head and recovered quickly, her condition was normal again. "Crikey! Tails that was ripper. those lights were so beautiful and amazing! I'm not sure what that whole light show was about but still I loved it. Still, nothing is happening to me I am a little dizzy but I feel fine." she said while examine her self and checking if her body was still whole in one piece. Tails took a good look at Marine and she was still the same as she was wearing her usual lime green tube top with white trim and black skin-tight shorts and lime green and orange sneakers. "Gosh I guess it didn't work, either there's something wrong with the machine or it has no effect on some people." he said with concern, he decided to check on his invention one more time, but before he could, Marine felt an electric jolt in her chest and yelped and stood up straight. "Holy Cow! Crikey." she cried, Tails ran over to the Raccoon girl and spoke to her in shock. "Whats wrong Marine?" Marine stammered for a moment and then she looked down at her chest. "My chest i-i-i-i-it's it t-t-t-t-…Tickles!!! hee hee" she said giggling then started laughing while she looked down at her chest as she felt an electric tingling sensation in her chest. Then she saw two small bumps appear in her tube top and then the bumps on Marine's chest began to grow, bigger and bigger and they stretched inside her tube top while her tube top stretched as well barely covering the raccoon girl's exposed mid-section. Tails and Marine watched in amazement as the two round objects attached to Marine's chest continued to grow larger until they were the same size as Rouge the Bat's tits. Finally they stopped, Marine looked down at her chest feeling it was a bit heavy but not too heavy. She was shocked in amazement seeing two big and soft orange colored orbs on her chest and were the size of an I-cup, she walked over to a nearby mirror to look at herself while her breasts were bouncing and jiggling for every time she moved her feet and took a step. Tails watching Marine of course his eyes were focused on her boobs causing him to blush and almost nearly get a nosebleed, Marine took a good look at herself and looked down at her chest again. "Oh!" she exclaimed blushing and started moving only her upper body left and right making her boobs jiggle. "Ooooooooooohhhh" she moaned in a soothing tone giggling and smiling while looking at herself, "I look so so s-s-so….Sexy." then she moved her head turning her attention toward Tails, her eyes half-way shut but still looking at him noticing he was staring at her blushing, eyes wide open and blushing just looking at her. Marine giggled at his embarrassment and then she started walking towards him while her boobs were bouncing and as she got closer to him, she lifted her hand up and tickled Tails' chin with her finger while giving him a sexy smile. "You used your machine to give me some nice big tits did you?" she said in a sexy tone, "Uh-uh-uh-Uhhhhhhh Yup I figured you look really nice and beautiful with your newly developed chest." Tails said blushing, Marine giggled from his comment and came up to him and kissed him on the cheek and gave him a hug while bringing his head and pressing his face close into her big breasts. "Awwwww! that's so sweet, thank you thank you." she said, Tails began to blush even more seeing how close his face was to her chest but he was happy and he figured he could have a little fun with Marine.

*

Tails' embarrassment didn't stop him from blurting out, "H-Hey Marine! I know it might be weird now, and it's ok if you don't wanna, but are we still gonna go down to the beach?"
Tails scratched the back of his head, glancing away from Marine's big breasts. While they were equal in size to Rouge's, on her smaller frame, they looked gigantic. He kept muttering excuses.
"Tails, it's alright. Of course we can!" Marine laughed, and then hugged him firmly, burying his face in her bosom. Her strained lime tube top creaked audibly under all the pressure, but they were out the door before Tails could catch his breath! Marine sure did have a lot of energy. It was alright though, Tails was used to being the sidekick, and the view was much nicer behind Marine. One thing he finally noticed... The rest of Marine's body hadn't changed. Still, he did fancy her, gazing over her toned, athletic body.
"Tails, look out for that pothole in the trail there!" Marine warned, but Tails was watching Marine's breasts swing around her narrow torso, catching a glance at a nipple as they swung from side to si--Tails took a spill, dropped their duffle bag and got a mouthful of mud.
"Awww crickey, Tails! I'm sorry about that. I got in such a rush!" Marine frowned, helping the clumsy fox up.
"N-no don't blame yourself, I wasn't paying.." Tails looked down Marine's top, trailing off.
"Attention, right! Mmhmm! Right!" Marine snickered, and slapped Tails on the back, making him stumble into her jiggly chest. He recoiled back, flustered at how forward she'd become!

They got to the beach. Briny air, gull calls in the distance. The water sparkled, foam hissing as the tide receded. The cove was set against a steep, arching cliff that raked the sky with its jagged claws. Then Tails' gaze fell on the sound of clothes ruffling. It was Marine, who was shamelessly nude, pulling on her bikini bottom. He couldn't see anything, but he could see enough from behind her. He crossed his legs and grabbed the duffle bag, concealing his fierce erection.
Marine glanced back at her wide-eyed companion and snickered, "C'mon there, Tails. Why don'tchya help me put on my top? It's in the bag."
Tails nodded vacantly, digging past the miniaturized scuba gear, packed lunches and assorted items to get to the lime green bikini top. He lifted it up, and grumbled nervously.
"Uhh? Marine?" Tails squeaked. She was facing away, hands on her hips, finger tapping impatiently.
"C'mon now, Tails. It'll fix me. I just need you to help me tie it on tight. Get on with it! It'll be fun!" Marine curtly commanded, adding a little giggle to help set Tails at ease.
He got up and leaned over Marine. She covered her nipples, but the memory of them poking through her top was vivid. He closed his eyes and let her hold the triangle-cut cups over her nipples. He tied the straps behind her back, finding that they were so short that he really had to strain to pull them into a knot. Marine was grunting, too, but encouraged him that it felt comfortable. Her breasts kept squeezing around her body as the bikini top tightened up more and more, the triangle cups stretched out, too, getting thinner, discoloring as they revealed her pinkish nipples through the green, sheer fabric.
"There! Finally!" Tails clapped his hands, and Marine swung around and pulled down Tails' pants.
He yelped, but Marine winked and snickered, running away into the water while Tails put on his actual swim trunks.
"That wasn't very nice!" he called, stumbling as he pulled his shorts up while running.
"Well, what're ya gonna do about it, foxy bloke?" Marine laughed, swimming on her back in the shallows...

Tails huffed, tying the laces on his trunks up tight, almost defiantly after Marine's prank. He walked back to their duffle bag and dug out the scuba gear. It was his own invention, a little twin tails icon etched into every part. Marine swam in circles, watching him with her keen eyes, and got excited, calling out, "Oi, Tails! Hurry along with that!" She doggy paddled back to shore as Tails was returning, and stood up tall. Tails blushed, eyes darting about a bit, embarrassed about his attraction.
"Aw. Hey Tails, it's ok. I wanted this, right?" She leaned over, her jubbly breasts threatening to slide out of her wet bikini. Marine tipped Tails' chin up, and took the flippers and gear. She put the goggles up on her head.
Tails was still embarrassed, "Ahaha, well if you say so." Tails looked at Marine, thinking the goggles fit her well. She flicked him right in the nose. 
"H-heyy! Hey wait!" Tails called after Marine, but she took off again, swinging her chest around wildly, almost using the heavy swaying to carry her forward in long strides. He started after her, but stopped to check his gear was in order. He was so mixed up by her.
"C'mon, Tails, if ya catch me, I'll make ya my first mate!" Marine teased, already floating in the shallows. "Ya gotta get wet eventually! The water's fine!"
Tails scrunched his nose, "I know it's fine, ok?! J-just hold on, I'm coming!" Tails joined her, and she seemed to calm, though Tails feared that her smile and quiet was masking whatever other prank she had planned.

The tide didn't wait for anybody though, but the day was still long. Tails lead the way, but as they swam into the deep, Marine's sharp senses, lead them away from the danger of powerful currents and places where stinging fish nested.
"It's not too far from here now!" Tails said, pointing toward an odd, darker patch in the ocean. They weren't too far off from the coast. The whole of the coastline and its mountains still well in sight.
"Tails, how'd a runt like you get out here on just this dinky respirator and goggles?" Marine and Tails slowed down, wading toward the undersea object.
"Y'know, I never really thought about it Mari--HEY I'm not a runt! I get in all kinds of danger and fight all kinds of jerks!" Tails shot back.
"Ahahah! Calm down, foxy! Cry-keee, I was only payin' you a compliment! I'm impressed! honest!" Marine smiled generously, pulled her goggles down, and giggled," And I know how hard you work on all this gear. I wouldn't trust anyone else to design my gear!"
"Well.. It's my gear, but you can keep it if you want," Tails grumbled.
"Aw, c'mon, don't be like that. I wanna see what you brought me out here for. What is it, what is it?" She was grinning, and Tails smirked back.
"You'll see... Follow me, I know how to get inside." He dropped his goggles and put on his respirator. The air line looped back to a small canister of oxygen and a secondary of helium, in the event of a deep dive. Marine noticed it finally when she went underwater, and thought she'd use that to tease Tails some more, since they didn't weren't going to be going so deep underwater to need it. She only noticed it because as soon as the oxygen started flowing, a HUD appeared in her vision, showing the remaining O2 left in the tank, their depth, and a radio signal.

It was some sort of tower... No wait! It was the wreckage of the Egg Carrier! It was already covered in coral reef. The intact sections were rotten, rusted, but the rainbow of tropical fish and arrangements of reef were beautiful.

"Tails, this is amazing! The sea's put that old Eggman's skeletons to good use," Marine radioed. Tails flipped around, swimming backwards and smiled, throwing a thumbs up.
"Oh, wait until we get inside! I think you'll be even more impressed," Tails bragged.
They were nearing the dead behemoth. The nose of the wreck wasn't in sight. The ocean was crystal clear, untouched by most any pollution. That only added to the scale of the monolithic mega-battleship. There was a great droning emanating from the ship.
"Tails?" Marine worried for the first time.
"It's ok. That's normal. I can assure you that it's not going to break apart, but it is bending with the currents," Tails explained. "No need to get scared!" 
Marine sighed over the radio, but they finally came to rest at one of the airlocks, which, to Marine's surprise, was still functional?! Tails waved her over, opening the door.
"Criii-key," Marine drawled, "Gotta hand it to the Eggbloke. He builds it to last when he really wants to."
The door gurgled, pulling water inside of it. The door slid open slowly. Deep, rumbling as it strained its rusted machinery. They swam inside, shooing away any curious little fish that poked in.
The water flushed away after the door closed. Heavy locked slammed into place, shaking the wide room. The inner doors yawned open, their motors whining under duress.
"Could do with a spritz of oil though huh?" Marine said, having already taken off her mask.
"It'll be fine, I promi--Oh you're joking, ahaha," Tails smiled nervously, hanging his flippers up. He had some wading boot versions of his shoes hung up, and offered a pair to Marine.
She peered at the offer, taking it on while wondering, "It's like you live here or somethin', Tails."
"Well! Yeah! It's my home away from home, where I can work without interruption from Sonic and everyone else. I can think here quietly," Tails said. "I was kinda hoping that you'd be more impressed actually... This thing was dead when I came to examine it and decontaminate it, but, it was mostly intact, so.. I.. maybe sorta maybe kinda lied about scuttling it."
"Well that's a rotten trick to play on your friends, isn't it? Makin' your very own secret underwater lab and not tellin' a soul about it," Marine smirked. She wrapped her arms around him, smooshing her big breasts into his back and snickered, "I'm glad ya shared it with your bestie, Marine, though."
Tails' fur fluffed up in response and he stammered, "G-g-good! I'm.. I knew.. th-that someone so mech..mechanical.. ly inclined as y-you would appreciate th.th.."
"Oh Tails, it's wonderful! You're amazing. Show me around," Marine gushed, letting the poor fox go before he fainted.

"Alright! Let's go!" Tails said, feeling proud about impressing her. Marine, meanwhile wondered when he'd get on with kissing her, but had a good time of teasing him for now.

They hadn't gone much further than the airlock and its ready room. The door was sideways. Tails had to pump a lever beside the door to fire up its keypad, saying, "Well, not everything's perfect is it?" "Spose not, Tails," Marine said. They were standing on top of lockers. She looked up, then at the walls. The ceiling was to her left. Oh right, the ship crashed sideways, stuck in the seabed upright like a massive dart. They entered the ship proper, having to amble down a series of ladder rungs that Tails must've welded to the wall. There were neon ropes and cables strung through the air, lamps hanging from them. No matter where they went, water hissed out from between the breaks in the bulkheads, leaving puddles and shallow rivers running just about everywhere. It was cold inside the ship. Emergency lights were on, too, bathing the upturned deck in a gentle yellow glow. Guide lights were only good for marking key areas of the ship, but plenty of them were red, marking areas that probably broke off in the crash.  They came to another door, another hole in the ground really. "Well. Strap in, Marine! We'll be there pretty soon!" Tails offered her a harness. She attached its belt buckle to one of the ropes, and down the hallway they went. It was well-lit for most of the way.  "Funny how this all used to be turned up right huh? All the chairs and stuff're welded into the floor," Marine said, taking a seat on the side of one such couch.  "Y-yeah, but be careful okay?" Tails warned, and prophetically, the metallic couch gave a lurch. Marine planted her feet on it and leapt from the furniture before it dislodged. She yelped, clinging to her climbing line, swaying and bumping into the walls. The couch banged off the walls, smashing lamps and snagged their lines before it hit the floor, giving them a great lurch downward. "Ohhhhh no!" Marine yelped. Tails gasped, and reached for Marine instinctively. He grabbed her hand and she hugged him tightly. "See? I told you to be careful, Marine!" Tails chided, but Marine giggled, sniffled, and replied, "H-hey we're not dead, no foul, eh?"  They were both shaken, but together, they made it down the deep hallway. They There was an alternate way down, but this was the fastest. Tails worried that he might've not done the best job refurbishing the carrier. There it was, the killer couch. It was blocking the doorway. Tails set the door to open manually.  "I don't wanna drop it on anything else, so I'll just crack it open," he said, opening the side panel and pumping the lever inside. The door creaked open little by little.  There were more rungs on the wall. Marine went ahead, Tails holding onto her, but she got stuck. "Oi, Tails, give it another crank, eh?" she said impatiently, letting her breasts rest on the door. He blushed, eyeing Marine's high beams, remembering how cold it got in the ship, and widened the gap so that she could climb down before she noticed his gaze. They detached themselves from the cables, but kept the harnesses. The rest of the journey through the winding, upturned halls was less exciting, thankfully...
"We're home away from home!" Tails said, throwing up his arms. They were in the atrium. A massive tree dominated the deck and it was clear that it had punched through the ship itself from its overgrowth. Tails had cut holes into the former floors, too, following the larger branches. Scrap and wooden planks formed the floorboards.
"Let's get in soon and warm you up," Tails said. Marine snerked, rolling her eyes and strolled into the massive, seemingly slapdash treehouse.
The lobby hung in the air, with some of the rooms made by hollowing out some of the super-massive branches. Actual furniture was here, too, and Marine leapt onto the bed and covered up in the blankets, overjoyed to feel warmth return to her body.
She looked across to Tails, who was working some computer. Everything was welded down, too. There were numerous windows giving a view out to the ocean. Sunrays wavered with great glittering schools of fish.
Tails fired up the room's power. The room started humming, like some rotating wheel spooling up to an even speed. All his lab equipment made itself known. Robotic arms emerged from large pods in the walls and like the other rooms, cables and lamps webbed the air, the branches, and gave power to all of the salvage.
Tails smiled, rolling a heater over to the modest bedroom and sat with Marine.
"So here it is, my little private paradise."
"It's very pretty, Miles. Top choice," she murmured, looking out of the round frame, allowing herself to lean on him. Tails looped an arm over her shoulder and leaned back. They admired the view. The sunlamps were powering up as the emergency lighting powered down, illuminating dust in great beams. Buds that had blended into the great tree's foliage stirred. They popped open dramatically. Red, yellow, green.. all sorts of colors. The flowers looked like lilies as big as your head! One of them bloomed right over the frame of the door. Sparkling purple pollen fizzled down from each bloom.
"Sp--Splendid heaven," Marine was in awe. Tails was at ease. As they breathed in the magical atmosphere, the pollen they inhaled had a relaxing effect on them. Tails knew about it. 
"Yeah, it really is. The flowers are a hobby of mine, too," Tails murmured, laying down with Marine. "It helps me think. I mean.. The flowers help me. Rather umn.. Not overthink." 
She felt the effect hit her, too, "Oh y'mean get stoned?"
Tails laughed, "Well. It helps me get inspired."
She smirked, unwrapping from the blankets to let Tails in and he accepted, pressing against Marine's body. He didn't say anything else, planting his lips on hers. "Mmnnmnm.."
Tails rubbed Marine's big breasts, sliding his hands beneath her tight top, massaging right over her nipples until they grew stiff. Marine had her hand in Tails' trunks, squeezing his shaft from base to tip just firmly enough to make it tense. She slid a few inches away from Tails abruptly and squeezed her breasts together, his hand snagged under the top and whispered, "Oi, Tails. I got these for a reason, y'know."
She reached behind her and popped the top's knot. Her bikini sprung up as her big tits swung around, released from the tense, tortured top. Tails smiled, sat up, wriggled out of his trunks and crawled onto Marine, who leaned back, grasped Tails' dick and slid it between her breasts.
Tails pressed his hands against the bed's backboard, balanced, while Marine stroked his dick between her breasts.
He pumped his hips a little, but mostly enjoyed the jiggly heat slapping his dick around. He gasped and moaned while Marine giggled.
"Mmmn. Miles, I'm glad you warmed up after being cold, too," she teased.
Tails choked a bit, laughing, "I.. I y'know. I've always had a crush on you. I'm . haha." 
"I know, foxy," Marine giggled. She pressed her hands against Tails' belly, pushing him onto his back, leaving him needy, she hoped. She wasn't too experienced, but when Rouge the Bat exists, you tend to pick up a few tips from the videos she'd produced in her odd jobs.

Marine rested her big breasts right on Tails' lap, crawled up his body with a deliberately slowness, dragging her knockers along. Tails shuddered, feeling cum spurt from his dick already, but Marine was working his dick in her hand, peppering little kisses up his lithe body. She kept him hard, even after that orgasm.

"Hhahhhh.. Hhh.. M..Marine~" Tails whimpered, biting his lip while she both worshiped and dominated him. Tails languidly looked down at his predatory lover. She sat on his lap, rose to her knees, and then sat on his dick. She was still wearing her bikini bottom, but had slid the fabric to the side. 
She was so tight! He was so big! 
"Ahh!" Marine gasped, then purred, "C'mon, Miles. Mmnn.. My turn."
Tails couldn't respond clearly with Marine's big tits in his face. He groped her hips, rubbed her toned ass and started thrusting his hips. All the years of running around paid off so much that he surprised himself at first, the sight of Marine bouncing up so high. 
The wet affair continued. Tails sucked on Marine's nipples, becoming so impassioned that he occasionally bit on them to stretch them out, letting them flick back like stretched bands.
"Ahh! Not so rough, Miles!!" She yelped, so Tails licked and kissed it better. Marine ended up on her back again, cooing and moaning more and more loudly. "Y..yes.. Ah that .. There.. Yes!"
They were laid sideways across the big bed, Tails with one foot on the ground, ramming Marine wildly. While the bed frame was welded to the flooring, the mattress and blankets certainly weren't! 
They ended up on the floor with the whole bed spread after their extravagant fucking. Tails buried his face between Marine's big breasts. They embraced, and Tails seized up, experiencing a second orgasm. The sensation was much more intense the second time over. Very raw, bordering on pain. He groaned for a moment, transitioning into an airy sigh.
Marine smiled, sharing in the radiant glow.
"Well it's about bloody time, Miles," she said, squeezing him tightly. He laughed gently, tilting his head up to peck Miles on the chin. 
They snuggled up after pushing the mattress back onto the bed. Too high on eachother, and the pollen, they didn't notice through the windows that the sunlight cast down through the ocean had been blotted out, and ignored the groan and shudder of the ship...

Outside, the storm was raging, driving large waves up onto the shore they'd been earlier. Their duffel bag was washed out to sea in the time they slept. Trees bent with the storm, having survived much worse. The currents bent around the massive ship, the mountain of steel swayed back and forth, grinding deeper into the ocean bed. Nonetheless, the wildlife lingered near it, shielded from the powerful currents in its wake.
Marine was the first to awaken. She was used to a life with the sea, but deep within the broken down Egg Carrier, it was still alien. It made worrisome noises, metallic croaking, the ever present hiss of water spraying into the ship and occasional chugging of a pump clearing out excess flooding. The tree had fallen asleep, its flowers all mostly sealed away. It was as though they were never there.
She stretched, being careful not to stir Tails, and put on some of the spare clothes that were hanging in the bedroom. She picked out a shirt that said Angel Island Search and Rescue on it. The lettering stretched across her bust, and the shirt hung out from her stomach. She pulled her bikini bottoms back on. They'd dried off. They must've been asleep for quite some time.
Looking out as she walked to the central area, close to the trunk of the titanic tree, she noticed a workshop area. Plans and blueprints were rolled up, and even more were tacked to the shanty-like walls. There was more plate steel welded up in the work area though. The machinery there wasn't too different from the stuff inside of Tails' proper workshop, but much of the cobbled-together appliances had scratched-off Eggman icons on it. It was all arcane to her, so she leaned on one of the guard rails after giving it a cautionary shove, remembering the earlier incident. She looked out. It was very dark, and the bubble streams whipped about excitedly. Occasionally the depths lit up momentarily. It was storming, but down so deep, the noise of it didn't register, just the dim rush of water straining the ship's bones.

Tails had awoken, dressed in a plain white shirt, though it was stained by old oil splatters. He came upon Marine, admiring her, watching her shift her weight around against the railing. Her breasts were so big that they were plainly visible from behind, swaying beneath her arms. 

"Oh! There you are," Tails said. Marine startled, and straightened up. "Ahah, sorry!"
"Oi! I was distracted! I think it's stormin', Tails," she said, but Tails smiled and waved his hand.
"Don't worry. The sensors would've tripped if there was any problem!" Tails assured.
"Sometimes I think you trust design more than the mechanics of it, Tails," she sighed.
"Aw c'mon, I fix plenty of stuff!" Tails insisted, and Marine sighed, not bothering to bring up that he crashed the stuff to begin with, often due to breakdowns.
"Well alright, I'll relax. So what's all this then?" She waved her arm around to the familiar array of lasers. Arranged in a circle, numerous rings up the side of a large glass chamber. "That's your machine isn't it?"
"Oh yeah, that's the second prototype actually. The one back in the shop is based on the first design," he said. "It's a lot more stable, and it can draw on the ship's own generator, which I then filtered through these Chaos Drives on the back of each emitter.."
Chaos Drives, Marine reminded herself, were simulated Chaos Emeralds. Tails was distracted with pointing out every aspect of the machine, explaining why he left certain parts of it unshielded, and the difficulty of finding all the parts. She walked up behind him, rubbing his shoulders, which broke his his entranced over-explanation. 
"Y'know, Tails, I was thinkin' maybe.. Y'could do with some improvement to your own design," she giggled.
"Uh..Oh.. Oh what .. I mean sure. What do you eheh.. Propose?" Tails snickered, still a bit nervous around his crush. Marine's hand glid down his belly, resting on the lip of his waistband.
"Well, I was thinkin' that you could pump this up even more," Marine said, her big breasts pressing against his back. "Didja think I didn't notice that you gave yourself a lil boost before?"
Tails blushed fiercely, "Y..You.. You really like that?"
Marine giggled, nodding whilst nosing his cheek. "Yeah, I suppose I discovered last night that I have a particular love'a'being packed tight. While we're at it, I think I could do with havin' my trunk bulked up, too, to match the top, y'know."
Tails blushed, happy to be accommodating. He grabbed Marine's hand and pulled her along to the control console, gave her a rundown on how to run the device. It was simple. A little pixellated version of a Chao on the warbling monitor had a simple conversation on the requests, then spat out a preview of the results. 
Marine stood in front of the keyboard, feeling much at home in command of the powerful machine. It was still warming up. The Chaos Drives were electrified and began to levitate in their small containers, aligned to the beams and spun. Each one glowed a different color, even colors that were not native to the gemstones they imitated. Tails stood in the chamber and held onto the rails within it. The door slid closed, locks dropped, and the tips of all the emitters glowed. Their rails dropped down, matching his height and Marine asked, "Ready in there, foxy genius?"

"I'm ready when you are!" Tails replied, a little nervous, watching most of the emitters aim downward. Warmth filled his body when Marine hit 'go' She studied the wireframe of the 'current test subject' closely, watching the particles building up in his body, the majority of them pushing energy toward his groin... No changes quite yet... She bit her lip, half nervous, half excited.
"Feels good doesn't it?" Marine called.
"Y..yeah. I .. I haven't tried this version out. It's intense!" Tails gasped...
The lights flickered. Most of the sun lamps cut out.
"Th..that's normal! I think. It takes a lot of power to prime the Chaos Drives," Tails said.
It felt like a series of warm rings were stroking him. The edges of each ring started at his extremities, from the tips of his ears, toes, and fingers, the warmth drew inward, closing the ring from within his groin. The tight heat slid up his shaft and down his balls. The heat dissipated somewhat. It took a minute, but the sensation overload made seconds stretch into infinity. It was pleasurable, and his cock started to rise. He looked down, his snug boxers bulging out more.
"Is.. Is it working?" Marine called, noticing the preview starting to change to the size she had entered. 
"Hh-Ahh Sure? I think?" Tails strained out. It was. He wasn't hard yet, but it was slowly growing in time with each heartbeat. Each throb pushed more flesh out, pulling the waistband out from his belly. His balls were expanding as well, tugging the cotton fabric from his thighs around them. Even deep within him, his prostate was growing larger, leaving him with a rising sense of heft behind the root of his cock. It was the reason for the thick glob of precum oozing from the tip of his dick.
The emitters cooled down, but like being out to sea, he was still feeling the phantom of energy stroking his junk.
"It never felt this good before," Tails admitted. The door slid open automatically and Marine got a look at it finally. She reached out to touch it, almost afraid of it, but finally gasped, "Q..quite a beauty on ya, foxy." 
Tails' dick was still growing. As with Marine, the effect took time to run its course. It was already 9 inches long, and clearly not stiff. His balls were close to the size of apples. It drooled a long, thick strand of clear spunk. Marine smirked, leaning over to give Tails a kiss and said, "Well, I spose it's my turn right?"

Tails blushed, holding himself together just enough to walk over to the console, tucking his enormous dick across his hip, parallel to the waistband. The whole thing, even his nuts, throbbed. His balls especially made themselves known when he sat at the desk. He was incredibly horny, feeling cum drooling down the side of his hip, splattering loudly when it oozed down and dripped from the chair.

"All ready in here, Miles!" Marine said. Tails' fingers were shaky. Each throb rung in his head. It was so distracting.. He input the commands to widen Marine's hips and boost her height, much of that height in the lengthening of her legs...
He reached down rubbing his big dick. It filled his hand with its girth and then some. He stroked the slimy release down it and in moments, his shorts were soaked through.
He had to focus though.

Outside, the ship was digging deeper and deeper. The abandoned decks were flooding uncontrollably. The sides of the impact crater were tearing the bulkheads apart like they were as fragile as perforated paper. Patchy welds in the habitable decks were breaking open as the ship dug itself deeper. Even in the atrium, a few more leaks didn't even register to Tails as a dire warning. He was thinking with his dick for now.

The decks were still filling slowly. The great size of the egg carrier mitigated the damage being done to it, but it was reaching the tipping point. Some of the automatic locks were slamming into place to slow the flooding. Bilge pumps turned on more frequently and played a part in delaying an emergency being declared by the ship's faulty, damaged computer.
Tails laughed a little before realizing that Marine was banging on the inside of the locked test chamber.
"Oh sorry! Ahhah.. I.. Was just distracted. I still feel really umn.. Aroused," Tails said into a microphone. It piped his voice into the test chamber. 
Marine calmed down, impatient mostly, replying, "Well I'm sorry about that. We can try out your hot rod after you boost me up, alright, Miles?" Tails' mind drifted again, fantasizing about sex with her a second time.
He started typing, feeling woozy. He looked down. His dick looked even bigger than it was a few minutes ago. He started rubbing it firmly, typing with one hand. The computer took the commands, but he set the rate to persistent. 
"Hh.. M..Marine. Talk to me. I'm so horny," Tails begged, and turned on the machine.
The Chaos Drives were already warmed up. It didn't take long for them come to full intensity and bathe Marine in the same pleasurable heat that Tails was still feeling the effect of.
The flowers on the tree stirred, all glowing slightly...
"Ahh! Oh my. It's so warm," she gasped, but then she smacked her lips, thinking, "Well, first, I'd give you a little show, show off my big, wide hips and jiggly arse. Maybe squeeze into one of those wetsuits just so I can strrrrretch it out."
Tails peeled his dick out from his sloppy-wet boxer shorts. A pool of cum spilled out behind his long, heavy dong. A webby, wet sheet trailed behind it and splattered onto his belly. He stroked slowly, feeling it harden up and beat its glans against his chest.
"Uh..uh huhhh? I'm imagining that," Tails rasped, watching the energies building up in Marine's body on the screen.
Marine stroked her hips, "Ooh, I can feel it, Miles. It's .. It's much faster than the other machine. Mmnn. My skin is so bloody hot. It's like I'm being massaged all over." Her toned bottom filled out slowly. Her hips widened, making odd rubbery noises as it developed. She felt muscles deep inside her tensing up. As they relaxed, her legs grew longer. Her arms, too. She was getting taller, but much of it was gained in her legs.
In minutes, she looked much more mature, far more voluptuous, matching Rouge's sex appeal.
"Ohhh Tails, you've made me perfect," Marine gasped as the machine kept bathing her in waves of pleasure.
"Mmnn..Hhnn.. S..So.. I was.. W..wondering.. How much you wanted again," Tails asked, the sound of his masturbation carried through the speaker. "I.. I think just a little more will make you *gasp* compatible.. With my enhancement."
Marine blushed intensely, overcome by pleasure herself and permitted it, "Yeah. Yeah you're right" She felt the pressure, the familiar heat, spreading to her chest... On Tails' monitor, he was inputting growth commands into Marine's preview wireframe, masturbating faster and faster, making her breasts grow progressively larger. The machine's beam emitters grew brighter, all aligning to aim at Marine's tits. While they fit her body perfectly, he was ready to blimp her up. The beams fired into Marine's chest for a split second, making her yowl and then giggle.
"Ahhh! Ehehehe! Th..That. Tickled? Oh. OH!" Marine rubbed her breasts, feeling that heat intensifying rapidly. "T-Tails! Wh..Wait! I.. Whh..Ahhh! Did you do to me?" Her voice had a breathy tone, overcome with sexual pleasure despite her doubt.
"D-don't worry, Marine. Hhhnnmm. We can.. We can undo the changes," Tails laughed, licking his lips, "Turnabout's fair play, and I promise.. Y..you'll get what you want." Pop! The speaker cut out. Tails tossed the mic over on accident, feeling an orgasm rip through his body. His enormous dick fired shot after shot of semen and all he could do for the few seconds was lean over the keyboard while trembling, moaning loudly enough for Marine to catch a bit of the noise. She could see him recover, too, and noticed how hard it remained, thumping against the bottom of the desk after ejaculating enough to fill a gallon jug and still drooling in need afterward.
She leaned against the rail inside the chamber, arching her back, feeling the throbbing in her breasts getting insistent as they grew again. Her nipples pushed out, becoming thicker, longer, tenting the Search'n'Rescue shirt's design, pulling it tight across her swelling breasts.
Their shape had an unearthly, unnatural shape. They were slightly sagging, but they were ovoid and round, like big water balloons. She gasped, looking down into her deepening cleavage, watching her tits push further away from her body, starting to spread beyond the width of her shoulders.
She cupped the big basketball tits, rubbing them. An unearthly softness and growing weight pulling on her upper body. She pinched her nipples, biting her lip at the buzzing pleasure. She weathered it, watching the nipple stiffen, pushing out so far that it could've easily filled a shot glass! The areolas they were mounted on were as wide as soup bowls, and nearly as deep. Milk squirted from them as she tugged.
"Hhhghnnn, Yy...yessss," she hissed, and Tails grinned, happy to hear it over the intercom. Marine's hips kept ballooning as well, her asscheeks so fat and wobbly that her bikini bottom, formerly quite concealing, was pulled into a thong. Soft, fatty flesh welled out over the straps and dug into Marine's puffy pussy. Even for her increased height, it seemed more substantial. Femininity and sexuality magnified in her form. 
The machines begun to cool and Tails sighed, "The machines are overheating." His dick smacked into the desk's underside and he winced. He bit his lip and punched in a command, re-routing backup power to the lab grid. The extra jolt overloaded the Chaos Drives, making them all rise to a brilliant white. 
Marine stiffened up. The energetic 'rings' that were rolling up and down her body exploded in frequency and intensity. She vibrated for a few moments, and the machines stopped with an unceremonious THUNK. Steam poured from their cooling vents. The door slid open.
Marine was spent though, and just barely stumbled out before sitting on her knees to catch her breath...

Tails walked over, his footlong dick swinging out in front of him. 
"Mmn.. We're not done..y-yet," he said. Marine nodded, " J-just lemme catch..Mm! AH!"
Tails shoved his dick into the underside of Marine's massive breasts, groping her huge nipples like handlebars. Tails closed his eyes, pumping his hips against her soft, heavy bosom. "Y..you just rest, Mmmn..rine," he gasped. The overcharged pulse began to blossom within Marine. She started to giggle, "I..I feel. th-the tickle! Again!"
Her basketball-sized tits began to get heavier, appearing to inflate like balloons. Her mammaries spread over her chest, becoming so enormous that her shirt began to shred apart, letting her watermelons breathe. Her nipples ballooned into teats, the areolae beneath them had swollen to the size of most womens' breasts! Tails noticed it when he found it hard to hold onto her milk-slick nipples...
Her hips continued to widen, making her look so exaggeratedly hourglass that she resembled many fertility idols.
Tails smiled, saying, "I see that transformation finally finished." He held in his hands, her enormous nipple, fingering it. Marine nearly collapsed entirely landing on her knees. Her breasts smothered Tails from his feet to his chest, still rumbling as they grew ever larger, a pair of beachballs that projected out from Marine's torso by at least 2 feet.
He crawled out from beneath her ballooned lover and groped her nipple, pressing the tip of it to the tip of his dick while Marine looked on with wild eyes.
Before she could even gasp, Tails shoved in, drool hanging from his grinning lips. A full foot of incredibly thick dick slid inside her breast, causing Marine's nipple to distort, bloating around his shaft. The milk was oddly thick, but slippery, just as he programmed the machine to do for this.
Tails pounded Marine's breast, and the hypersensitivity was all it took to convince Marine to accept it. She was whispering, "Yes, Yesss. Ohhh god." His hips slammed into the soft mass, causing the nipple and areolae to pancake beneath his force. He was squeezing down so much on her breast during its growth that he actually felt some of the odd fluid squeezing inside of him.
Tails trembled, eyes rolling back in his head, letting it happen, feeling the leaden heat settle in his balls. He leaned in further and further, feeling the fat flesh squeeze around hips and Marine felt it, too, feeling his nuts expanding as they hung lower, resting on her bosom.
He fell backward, grunting. A fountain of cum and odd milk sprayed from the tip of her nipple, trailing his dick. His junk looked far more swollen than usual, veins throbbing sorely on its plumped length and inflated nuts. Previously apple-sized, now close to grapefruit.
Marine calmed first, despite her sorely used nipple. When she stood, she towered over Tails, "My goodness, foxy~ I feel like a bloody giantess."
She leaned down, squatting over Tails and grabbed his dick. It'd bloated to a length of 14 inches, as stiff as a bar. "Ahh, is this for me?" She asked, stroking the hand over-filling shaft. She pressed her finger over the tip, plugging the persistent gush of precum, which made Tails wince and squirm.
"Ah..Ah.. Ahhh! D..don't," Tails begged, but Marine was captain again, her massive knockers keeping Tails concealed, her long legs and thickly powerful thighs locking him between them.
"Now, now, first mate Prower, no cumming again until Captain Marine's say so," she commanded, slowing her stroking, contemplating her next move.

Marine towered over Tails, double his average height at least. She was powerful. Her thighs were easily wider around than his whole body. Not only did every bit of her jiggle, but the presence of muscle bore down on his slender hips when she locked her legs around his body. Her massive breasts swayed over his head, tickling his eartips. She had one hand on his tool, rubbing it lovingly and felt the endlessly drooling semen pooling in her lap.
"Now then, Foxyboy. Looks like your machine's right outta order. Well, I betcha I have just the fix for you," Marine giggled. Tails groaned, his shaft a ruddy, deep red and throbbing raw. That didn't dissuade her for a moment.
Marine lifted up Tails and slid his 14 incher between her big, gelatinous asscheeks and stuffed his body right against her plump, drooling pussy. She held him between her thighs and slowly made her way over to their bed and laid Tails out with a crude drop. Her vast ass crushed his narrow hips into the bedding.
"Mmn. That kinky spell of yours gave me an idea, Tails," she whispered, saying, "I figure that chaos machine'a'yers changed my milk. So, let's experiment, genius."
Tails was delirious, having just been overpowered by the womanly goddess he'd unleashed on himself. He was about to reply when Marine groped one of her mighty breasts and guided the milk-gushing nipple to his face. The spongey, soft flesh oozed into his mouth. When he swallowed, he felt a heady warmth fill his belly. Oddly thick cream filled his mouth and spurted out of the corners of his mouth while Marine milked her huge breast into his face, the flesh often rolling over him, smothering his face, before recoiling back with a jiggle. His stomach ached, beyond full, and then it hit him. A gurgling noise arose from within, and a bizarre rushing sensation flowed into his groin.
He knew what was happening, and let it happen. He reached up and helped Marine work the transformative milk out of her titanic chest. The hot tendrils within him pushed up the root of his dick, filling it with a sphere of pressure that fed more girth into it.
Marine moaned sweetly, "Oh my, it's working. Mnn. Well, foxy boy, we'd better not waste a drop, mmn?" She stood, a long line of slimy, sexual fluids drooling from between her thighs and took one of the climbing harnesses from the clothes rack and tied the elastics around the base of Tails' swollen penis.
"There... Not a drop!" Marine cooed, rubbing Tails' balls as they began to expand, drinking the heavy cream up from his belly. His nuts swelled, packing fuller with fertile cum, making his nutsac so crowded that it gained a slight sheen to it. Pulsing veins rose across each enormous testicle, but Marine only seemed hungry for more. She kneaded each fat nut, encouraging even more growth out of them. Soon, she could only push them up and down his shaft, as his ballsac had begun to draw so tight that she couldn't keep rolling them over eachother.
Marine laid on top of Tails, her huge breasts smothering his cock, even after it had swollen up an extra few inches, her titflesh enveloped it with room to spare. What Marine didn't realize is how intense her chaos radiation was. Tails was growing taller, but most of the growth centered on the fox's sexuality. Marine, too, was growing larger as she slowly rolled her massive milkers up and down Tails' lap and body. The energies soothed his stretched flesh, letting his ballsac loosen and thicken, allowing his cum factories to fatten up even more and comfortably so.
Marine slunk away again to appraise her handiwork and licked her lips. Tails gasped, trembling in pleasure. The harness bit into his dick cruelly and despite its bondage, broke away quite suddenly. A good couple flexes thickened his 20 inch long dick and shed the harness. A thick gout of cum pumped up his length slowly. He arched his back and cooed, feeling a lengthy orgasm wash over him, but Marine plugged the tip of his dick and grinned. Then, she groped it beneath the head and stroked down. Tails yowled and winced, feeling the fluid slide back into him, back into his bulky bowling ball-sized nuts, swelling them further.

"Ah, ah, ah, Prower. Your standing orders are to hold your fire," Marine lowed, and leaned in, rolling her beachball breasts over his lap and started licking his enormous shaft around its tip, sliding her tongue over the rim of the head while Tails tried so hard to maintain composure that he teared up, shaking terribly.
Marine rolled over, the bed broke beneath her great weight, and she laid on her belly... well, atop her massive breasts, and swayed her massive ass in front of Tails. Wordlessly, he mounted her, barely able to reach over or around the soft crest of her giant thighs. He slid his heavy, clumsy dick into her, feeling her soft thick-lipped pussy welcome him. The giantess clenched, practically sweeping him off his feet by his dick and crushed his face into one of her asscheeks. Marine rolled backward, sitting on Tails' lap and growled, feeling her boytoy fill her to the brim.
She grunted, doing squats, pressing her hands against the ceiling to push down even harder on the minuscule mate of hers. Milk and precum pooled beneath them. The floor trembled, and the whole tree the rooms were built into swayed as Marine pounded Tails. The interwoven branches groaned, some cracking audibly.
Marine glistened with sweat, gritting her teeth, wanting the pleasure to rise higher, and it did in a sense. Tails' shaft continued to expand, rising up into her deep vag, bulging her belly out rather grossly as it grew larger. Her body, miraculously elastic, stretched to accept the immense bulge. Her voice rose higher and more frantic until she begged, "Cum, Tails! Do it! Fill me up!" She leaned forward, and brought her spread knees together, crushing his balls between her soft, pillowy thighs.
He exploded inside of her. His huge nuts tightened to his groin, so huge that they spread his legs, and released their vast reservoirs into Marine's body. Each pull of semen was enough to fill a bucket. Marine's belly lurched out with each sloppy pulse, rising from pregnancy to quintuplets. Rising higher, making her seem like an overpacked broodmare. Her belly ballooned, outpacing the size of her tits, becoming so huge and firm that cum began to gush out between their bodies in a loud, slicky-gush.
Marine trembled in joy. Her eyes rolled back in her head. Tails, in the same deep ecstasy, cried out. Thick, gooey pleasure washed over them both.

When it ended, Marine crawled away to dismount from her hypertrophic mate and lifted his smaller body up against her breasts. As exhaustion took over, they fell asleep in eachothers embrace, and as the afterglow left them, their incredibly excessive size evaporated too. They were left with substantial changes though. Both of them were taller than they had been. Marine's breasts were quite huge, hips voluptuous and mighty, Tails quite hung, feeling a heavy churning in his balls.

The tree, punished by their sex, leaned to the side ever so slowly and touched the atrium's vast, multi-story tall window. The atrium window cracked...