Koi and Alkali Training

A Dewott and Dog-otter stood in the gym’s locker room, preparing their preworkout drinks, talking about the week’s work to catch up. Alkali and Koi only started working out together recently, but even now they had become fast friends. Their routine always involved brewing up a new preworkout to try for the day. The usual ingredients were spread out on Alkali’s locker shelves. C4 preworkout, caffeine supplements, creatine, BCAA Powder, and a set of brightly colored, neon, glowing glass bottles from Alkali’s lab. Alkali added the flavoring, Koi measured the creatine, Alkali started mixing it together, back and forth…

“Okay it’s just about done, ready to lift Alki?” Koi asked, pulling his tank top with ‘DIVE’ printed on over a thick set of pecs.

“There’s one more thing to add on that bottom shelf, could you grab it? I need to get my tennis shoes out of the car,” Alkali asked as he turned to leave the locker room.

Koi turned to look in the locker, and realized that there were multiple choices there.  He shrugged and opened the purple bottle, pouring an unidentified liquid into their shaker bottles. He was certain that everything in here was meant for their workouts, even if he didn’t know exactly what the scientific chemical stuff Alki used was called or how it worked.

The fact their preworkouts were glowing purple after the addition just meant it was working. Probably. He picked up the bottles and tossed one to Alkali when the Dewott returned to the lockers. It tasted like berries, sweet and citrusy, with a kick of something… some taste he couldn’t quite place. Chemical tasting but not unpleasant. They left the lockers together. Unsuspecting that their entire workout routines and lives were about to change for the much, much bigger.

—

Koi lifted his free weights in both hands, keeping time with the music playing overhead in the gym. “You’re getting big Alkali, getting that extra muscle,” the dog-otter hybrid commented.

The Dewott was resting on a bench, pushing weights up and down against his chest like a bench-press. “Yeah… but it’s getting harder too. No offense to your coaching,” he said, puffing as he set the weights down. He grumbled and scowled. “Think I’m hitting a plateau at this rate. Saw some results at first but now it’s slowing down, y’know?”

Koi rustled Alkali’s blue hair and put a hand on his shoulder. “Nah bro, it just takes a lot of time to get huge. You’re good. Getting huge.”

“I’d rather just use the growth rays…” Alkali grumbled. But he was smiling again at least, pushing away Koi’s hand. They picked up the remainder of their preworkout and chugged the bottle, leaving only a small layer of glowing, purple liquid at the bottom. Their arm muscles flexed involuntarily when he finished the drink, like a muscle spasm that slowly got stronger and… wait, were his muscles growing larger too?

Koi watched with wide eyes as his partner’s muscles expanded across his body, simultaneously, filling his workout shorts and sleeveless tanktop until it was tight across his body. Koi's dick started getting hard next, mirroring the lifter's thoughts: this growth was hot, and he wanted to get bigger. Their protein shake kicked in at that moment too. His shorts tented out as Koi's dick thickened, starting to drip pre as it went from large to thicker than his thighs. He had to pull his pants off quickly, releasing the hyper package into open air and letting it flop across Alkali's shoulder next to the Dewott's face.

“Woah. Keep lifting, we're getting a crazy pump Alky,” Koi panted. With a grunt he felt the tank top start to rip apart along the shoulders and fabric seams. The dumbbells he curled shrank in his grip, weight decreasing in proportion to his arms getting thicker. Koi was amazed; pounds of muscle filling his body felt amazing, turning him on. So much that Koi had to take a moment to add even more weight to the dumbbell. He kept curling it, filled with as many weights as it could handle this time. One… two… three… and it was already too light once again. Huh. This gym wasn't going to be too useful soon. His dick throbbed again at the very idea of outgrowing the available equipment.

Then he finally noticed he was getting taller too, just as Alkali stood up only to the dotter's midriff. His abs were at face height with the Dewott. And with the way his stomach was gurgling, Koi was certain the growth wasn't finished yet either.

“Dude, keep lifting. It's gonna make you titanic!” Alkali said, putting one hand on Koi's abs and gently rubbing. It was real, completely hard, and Alky could feel the growth actually happening as it shifted higher.

The Dewott found himself distracted from his own workouts, especially when Koi's package was right at face height. His dick was as thick around as his arm now, even taking account the newfound muscle. He lifted it carefully with both hands and began rubbing. This change was incredible, and Alkali found his libido taking control as he moved from rubbing to actively jerking off Koi. Sure this was a public gym, but no one seemed interested in stopping them. Most people were watching instead, mouths agape at the duo of bodybuilding otters and the amazing physique they'd grown in minutes. Koi's panting and grunting deepened, shaking the ground with every lift.

Alkali couldn't quite believe this was happening. He'd always found Koi attractive, easy to talk to, energetic and fun. But the mutual workouts were just to help each other reach their goals. Now he was about to get Koi to cum very publicly, and- oh his own growth was starting up again too. The pectorals and traps around his head bulged, and his arms weren't nearly so tired holding up Koi's meat now. 

“Ooohhh,” the Dotter groaned, heavy drops of pre turning into thrusts between Alkali's palms. The floor of the gym was painted with thick ropes as he released the biggest load in his entire life.

Alky sat back against a wall, licking his hands clean after their more personal workout. “Man. I'm hungry now, you wanna go get something after we finish?”

“What? Uh, yeah that sounds… great. Just give me a sec,” Koi said, still catching his breath. The energy was already coming back to the dotter, puppy-like reserves of infinite energy ready to power him through. But he would need a second after a climax that intense.

“Does pizza sound good?” Koi continued, his tail wagging.

Alkali normally would have turned up his nose at that suggestion. Right after a workout? No. They needed something more substantial, healthier, more protein to help build muscle. But when his stomach growled angrily, the otter had second thoughts.

“Actually? Yeah, pizza sounds awesome.”

Both lifters had to bend down beneath doorframes to get back to the locker room. And their clothes were entirely too small, showing off their chests, pecs, and leaving nothing to the imagination with tightly outlined thighs and dicks. They spent another hour feeling each other up and getting off in the showers. Pizza could wait compared to their raging, testosterone-fueled boners.

—

Grunts and the clang of a heavy dumbbell rang in the gym as Koi finished his chest fly sets. The dotter wiped sweat from his forehead with an arm, enjoying the feeling of his pecs fighting for space with his arm as it moved. This workout routine explosively boosted his muscle building over the past few weeks. Make the muscle growth preworkout, lift and grow through the sets, and finally finish with some cooling down in the locker room and pizza. Then repeat, every day.

He noticed that his thoughts were more and more preoccupied with desires to grow, to get stronger. He wanted to be bigger. It was a constant need made only stronger every time he beat his PR in lifting or felt his muscles strain clothing and rub against each other. The jock otter didn't mind the change much either; extra motivation to grow was always welcome.

He also knew that the same feelings were affecting Alky, but maybe in a different way. Alkali was distracted, sitting on a bench nearby and drinking from his bulking shake. He'd finished his sets moments earlier. Now, he was feeling up his tummy with one hand and chugging with the other. Most of his growth was still in muscle but, another feature was starting to show itself: an unending hunger. Koi could buy as many meals, pizzas, and beers as he wanted for Alky. The otter would always, always ask for more. And somewhere deep in Koi's mind he thought that was hot, something to encourage more in Alky.

“Aaaahhhh,” the blue otter sighed happily as he finished. He pulled down on his tanktop and stood up, making sure the slight overhang he'd developed was covered.

“Alright, all finished? Let's head straight to the showers and-”

Alkali was already up against Koi's chest though, face to face and belly to abs to cut off his thoughts. “Yeah. Let's get right to that. I'm feeling much hornier and hungrier than usual,” he said. This close to each other, their chests and bellies touching, it was no surprise that they also started to feel tenting shorts against their bodies too.

—

What a difference a few weeks could make.

Since they started their workouts and taking the bulking shakes, Alkali’s body had completely outgrown his past clothes, furniture, vehicle, and most of the old gym equipment. Now he was a 10-foot-tall titan with bodybuilder muscles and a belly that hung over his lap toward his thighs. They didn't leave leftovers at their after-workout meals anymore. Alky was too hungry for it, even with Koi encouraging larger portions. The dotter was no slouch on growing either, bulking up with muscle more than he could have ever imagined at the start. His greed for his own growth was only shadowed by his blushing and desire to see Alkali even larger than that.

Alky stretched his arms up, a long stretch now that he was outside the gym and able to move without breaking his arms through the ceiling. He chugged the rest of his bulking shake with one hand on his hip.

Koi blushed as the Dewott’s belly slid into view, and stayed that way. The shirt didn’t come back down fully to cover the gut after Alky stopped stretching. It was an absolute tank now. Taut, round, soft and heavy. Koi wasn’t making a secret of staring at Alky’s belly anymore. It wasn’t an option to keep secret since his face was just about at belly-height compared to the Dewott. He looked up and made eye contact with Alky, suddenly heating up. Oh no. The Dewott was looking right down at him, and the boner between his legs. He grinned after seeing Koi blush.

Alky passed the empty shake jug to Koi. “Wanna help me with a second shake? I trust you for how big you make it and how heavy too. Fill my tank,” Alky said, drumming his other hand on his blue tummy and stepping forward to press it into Koi's face. “BWWWOOOORP. See? More space now.” He winked and Koi's tail began to wag. Now he had silent permission to go even further with rubbing or feeding.

—

Koi sucked the mouth-filling dick in front of him, sighing happily as the dewott held a hand on the top of his head keeping him on rhythm and supported. He was lost deep in focus for pleasing the giant otter. That dick felt warm and spurting pre into the back of his throat tasted salty and sweet. Alky’s other arm was busy with a barbell, used like a free weight. Pumping iron idly while being serviced by his own personal trainer.

That tiny gym has become more of a hindrance than help. The weights were too light. The gym wasn’t private enough. Or large enough anymore. Sometimes Koi and Alky would workout at the beach, most of the time outdoors at the lab or in a large testing space. Like tonight. They’d gone outdoors to enjoy the summer weather, and because this way any mess they made would be outdoors, not inside. Such as the flood filling Koi’s mouth right now as Alkali’s balls clenched and fired liters of seed.

“Phew. Mmmmmmm, good boy Koi. That felt amazing, but now I think the workout is over,” the Dewott said, setting down a dumbbell half the size of a car. His other hand pet the top of the puppy’s head gently, like a practiced form of aftercare. “Feeling good?”

“Ready for more. Let’s keep going,” Koi said, licking his muzzle to get any remaining cum clean.

Alky pulled his tanktop over his head and let the growth inhibitors he’d been using as wristbands come off. Koi’s eyes went wide as the Dewott expanded large enough to tower over a two story building. Alky was holding back his actual height this whole time? Just so they could keep working out together? Koi felt like it was a compliment. His second thought was ‘Holy shit he’s huge, maybe I can get another round with his cock later.’ The scientist-turned-titan bent down on hands and knees toward Koi, within licking distance of his face.

“Then let’s start with a special protein shake from you, and one of those growth shakes you make afterward. An extra-large one. We’ll need to replace those calories after all this work.”

Koi braced his back against a building when Alkali pushed him, a head the size of his torso starting to give him a macro-sized blowjob. He slurped with practiced efficiency and hunger for as much protein as he could milk out of the dotter. Koi’s head spun as he wasn’t given enough time to recover from taking Alkali’s ropes of cum. The jock puppy could feel his muscles starting to expand as it digested Alkali’s ‘shake.’ He imagined the both of them going back and forth this way, each one outgrowing the other and servicing their partner. Until the city dwindled away around their pecs, then waist, then down at their toes.

He couldn’t wait for it to get that far. Koi humped into the inviting Dewott mouth, fantasizing in his head about the next round of growth.