Late, late, far too late for an average man to be working in the evening, a dragon by the name of Shoryuu was burning through midnight oil like a wildfire through a dry forest. 
“Just a few more calculations and everything should be complete…” he mumbled, reaching up a scaled claw to brush some of the long, flowing white locks of hair away from his face. Sweat was beading down the bridge of his muzzle and his body was trembling, all signs of exhaustion from his dedication to the project, and his desire to see the culmination of many long nights of work.
The laboratory Shoryuu worked in was nothing truly spectacular; soft white walls of brick surrounded him on all sides in a room not much bigger than the average gymnasium, and much of it remained empty a good portion of the time. Grey concrete floors completed a rather dull look, but amidst all the normalcy, a large computer console sat near the back of the room, connected to a sizeable 70 inch monitor and at the moment, two large containment chambers, each housing a currently unconscious body. Wires flew from the tubes in all haphazard directions, some going up into the ceiling, others still into the walls and floor. There was little else in the room to occupy all of that space, but when the two creatures came to be awake, they would start to fully understand why that was the case.
Shoryuu’s bright white lab coat was cast to the floor as he hastened in his work, and the dark, onyx black of his scales stood stark against the white walls that surrounded him. Due to the nature of his work, he’d worn nothing under his lab coat, and he enjoyed the feeling of freedom that came along with disrobing. In the tubes, both of his test subjects were fully nude as well, and with perfectly good reason. “Looks like the computer has finished running all of the diagnostic tests, and mental capacity tests…they should both be safe to release. Gotta say, it’s about damn time!” Shoryuu cheered impatiently. The opaque fluids that filled the two containment tubes started to drain, and a quiet ding came from the computer console, confirming that all computer testing was complete, and now, the organic interface part of the test was due.
In the left tube, a perfectly normal looking vixen came to light, as the cloudy waters drained down off of her fur. Her eyes flicked open the moment that the water sank below her neck, and her ears twitched with the sound of water rushing out of her containment chamber. Shoryuu was pleased by the initial results; her name was Leandra, and she was far from any normal vixen. To some, she may not be considered a vulpine creature at all, as she was only partially organic. She was one of the first of a new breed of cyber-fox that Shoryuu had been ordered to test, and that testing would not be done by him alone.
In the right tube, a newer model of creation started to appear above the sinking waters, but she had no visible eyes to speak of. This model was Vesta, the first in a line of fiber-mechas known as a cyber-wolf. Though her appearance was remotely lupine, she had no artificial skin or fur, making her appear entirely cybernetic, a total contrast from Leandra. Though her body appeared to have a metallic figure, she was actually crafted entirely from internal robotics, surrounded safely and comfortably with a stretchy, rubbery base, not unlike silicone, meaning that she could certainly be molded to look more organic one day, if the tests called for it. 
Shoryuu was nearly drooling.
“I’m glad to see you’re both awake already,” he said, pressing a large, black button on his control console that lifted the glass tubes off of the two cybernetic ladies, who stayed standing in place. Though the diagnostic check made sure that they would be fully functional upon their release, they were still in something of a mindless state, acting just as a computer would; they could almost never act on their own, and had to be instructed in most cases, unless they were given programming to do so. Though Shoryuu didn’t create the two ladies, he was the dragon-demon in charge of testing out a programming of his own design upon them, one which would allow them to learn all of the basics of some very special sexual fetishes, they very ones that they had been designed to fulfill. “My name is Shoryuu, and I’m the scientist who has been helping to program you and prepare you for organic interface testing. I’ll also be the one who performs said testing with you…do you understand?”
Both cybernetic females nodded in an inorganically perfect unison, proving full well that the diagnostics and mental state tests worked like a charm. 
“Good. In that case, let’s waste no time in getting started. I’m sure you’ve both noticed my nudity, and if the mental state tests truly worked, you should both already be programmed to know what you should do with a male when he’s growing aroused in front of you. I give you permission to act accordingly.”
Between his legs, Shoryuu’s cock had grown long and stiff at the sight of the two nude cyberladies, and Leandra was the first to act. Without true conscious thought, she stepped forward off of her tube platform and down to the dragon who had commanded her, and knelt right before him. “I hope this pleases scientist Shoryuu,” came a programmed voice, peaceful and feminine as could be. With a pre-programmed gentle grip, Leandra applied the perfect amount of pressed to Shoryuu’s shaft as she curled her pawtips around it, and opened her maw to reveal a soft, synthetic tongue and throat, made to feel just as good, if not better than the real thing. Artificial lubricants dripped from the roof of her maw as she took Shoryuu’s tip into the warm, slick confines, and started to suck it with unnatural precision. 
Vesta stepped down only moments after, being slightly more machine than Leandra, she waited longer to process her command before deciding to act upon it. She was unable to display emotions due to her appearance, but somehow, Shoryuu thought he could almost feel desire coming off of her artificial body as she stepped ever closer to the lewd display before her. “I will please as instructed,” she said, her voice slightly less female and slightly more robotic in nature, but still, the words were pleasing to Shoryuu. He could hardly believe his luck as the cyber-wolf knelt down next to Leandra and adjusted herself in a way that no fully organic female ever could, so that she could get underneath and between his legs without harming her neck. A slick, stretchy feeling tongue, made of the same fibers as the rest of her body, slipped right between Shoryuu’s soft orbs, slurping right up along his sack to the base of his cock. With precision rhythm, Vesta made a timed pattern of her licks so that her tongue would meet to Leandra’s lips at the base of Shroryuu’s length, providing him with an extra level of pleasure.
“Ooh…wow…that feels incredible, girls…this is my kinda test,” Shoryuu praised both ladies as they worked what felt like magic over his genitals. Though he’d played with two females at once before, Shoryuu had never been with two girls who could work together so well before, and their teamwork was enough to already bring him near to a climax, but it was far, far too soon for that. “However, we’re…ngh…that’s good…we’re here to test your capabilities in another fashion, not just your ability to please a male, but to please certain males in specific. I can’t believe I’m saying this, but, I need you to stop for a moment.”
Precum splurted from the tip of Shoryuu’s lubricant soaked length, even as Leandra pulled back and away from it. “But Shoryuu, I find myself…enjoying this,” the cyber-vixen complained, and her eyes were made to match, drooping slightly along with her ears. If Shoryuu hadn’t known any better, he would have thought she was a real vixen who had been trained to be a pleasure slave, and that was a perfect indication of successful testing. Of course, the tone of her voice seemed to go a little beyond her programming, as if perhaps, she was actually starting to develop desire of her own will. 
I didn’t think that part of the programming would actually take, Shoryuu thought. I wonder if they really will develop a mechanized libido for me after all…
“Only because you have instructed it, Shoryuu. I wish to perform further actions,” Vesta added. She spoke just as she was programmed to, sounding as though she wished for nothing more than to pleasure whoever she had been assigned to. With one last lick that the dragon-demon hadn’t been expected, Vesta drew back from Shoryuu’s dripping sack and knelt upright in front of him, right next to Leandra. “What would the scientist have us do now?”
“For the sake of teaching you properly, I’ll be simple. You two ladies were each created with the capability to stretch far beyond organic limits in multiple ways, for males who have excessive semen to offer, or who have genitals that are far greater in size than average. Conveniently, I meet both criteria, and so, I performed all of the computer testing on you so that I might know the best methods to properly test your capacities, and we have a large, empty laboratory room here in case anything gets a little bit out of hand. Before this ends, I will have filled you both far beyond normal limits with my seed, and you’ll need to tell me how you respond to it. Do you both understand this?”
Again, both ladies nodded in perfect unison, and Shoryuu grinned deviously as he looked them over. The programming had worked out perfectly. Both ladies were eager to please and did exactly as they were instructed, and now, with a successful stretch test, more models could be made through the same process. Of course…even if the test was a failure, he was going to have fun conducting it.
Shoryuu’s eyes, two golden-yellow cores of light, started to glow fiercely, and the white horns atop his head appeared to elongate as he conjured up some of the demon energies stored in his body. “There are many methods to expand one’s body, ladies. I happen to be part demon, so mine come from magic spells…and using my magic, I can see just where your limits lie.”
Faint clouds of black dust and smoke shook off of his jet black scales, and as his eyes glowed ever brighter, the length of his already impressively sized cock started to grow. From the near foot that it already was, Leandra and Vesta watched with wonder as it passed two feet, and right on to three, easily far more than any organic being of any species could take. “We’ll start off modest. Leandra, put yourself in a bent over position on all fours, and spread your labia so that I might test you first.”
The cyber-vixen actually seemed to be lost, enchanted by the suddenly huge length and girth in front of her, but the mechanized part of her brain made her immediately comply and bend over in front of the lusty dragon. Without even having to touch them, Leandra was able to spread her outer lips wide apart, showing just how brightly the glistened in the laboratory lights. “I believe they call this doggy style, Shoryuu. I am ready for testing.”
Everything about Leandra was everything that a guy could ever ask for in a female. She complied without resistance, and there was lustful desire in each of her movements. Her voice was of the softest silk, colored black with her wishes to pleasure whoever she was assigned to. Her eyes, bright and filled with wonder, narrowed and gave the perfect ‘come fuck me’ look to Shoryuu, who certainly couldn’t turn down the invitation. Three feet long and thick as a small branch, the dragon-demon knelt behind Leandra and harshly speared her on his enchanted cock, watching with impressed delight as the cyber-vixen easily took the first two feet, and then, the internal working of her body took over, adjusting her vaginal cavity so that she could accommodate the third foot as well. Shoryuu nearly climaxed just at hilting his test subject, as every inch that he grew gave him even more nerve endings, meaning each extra inch of his cock was nothing short of another mile of pleasure for him. 
“Test subject…took it perfectly…ooooh yeah…and she maintained optimal tightness. That’s very good, Leandra. Use your internal engines to try and milk my cock while maintaining that depth, if you can,” Shoryuu instructed, though he found himself panting the whole time. Not surprisingly, he felt his mind going cloudy as he tried to remember exactly how he was supposed to give the instructions. It was a rare night indeed that he was actually able to find a female who could fit his magically endowed length.
Leandra’s maw flew open as she let out a perfectly feminine cry of pleasure, and her eyes winced tight as if she could actually feel the pain from being penetrated by something so great. “Yes, Shoryuu. Tell me, does this please you?” she asked, as artificial moans escaped her lungs, and her inner walls started to work and milk Shoryuu’s cock in a way that no natural woman ever could, with the exact precision and timing to send the dragon-demon right to the edge.
“Yes…that’s very good, Leandra! Keep on going, just like that…holy fuck…don’t stop!” Shoryuu cried out, having never anticipated that Leandra would already have such amazing control over her inner muscles. Every slick inch of artificial flesh inside of her clung perfectly to all the right spots on the dragon-demon’s massive cock, and already, copious amounts of precum were spilling forth, leaving a slight bulge on Leandra’s tummy. 
Sitting aside and watching didn’t seem to sit well with Vesta, who despite being fully robotic, seemed to be gaining a penchant for pleasuring her first user. “My sensors indicate that you may be close to an orgasm, Shoryuu. I’ll help you attain it,” she said, her voice as cold and calculated as it could be, but the intentions she had for the dragon were anything but. Seeing that his normal sized testicles had dropped down slightly and engorged to the size of oranges, Vesta stepped behind Shoryuu and grasped his sack from behind, squeezing and working the flesh of his orbs with a touch that could never be replicated, perfectly soft when his moans called for it, and a little more rough to keep his body just on the brink of orgasm, to help his pleasure continue building. 
“My body is ready for a greater test, Shoryuu. Please…don’t keep me waiting any longer!” Leandra pleaded, letting out a gasp that sounded and felt so real, Shoryuu was starting to question if she was really cybernetic at all. It wasn’t something that could be preprogrammed; it was the kind of moan that came from a female who was truly lost to the throes of passion, far and beyond the ability to fake her pleasure. 
The dragon-demon immediately delivered. Feeling the masterful touch of Vesta upon his sack and the perfectly tight squeeze of Leandra’s passage, Shoryuu gritted his fangs together, and his magical endowment released the first torrent of cum within Leandra, and like the bottom of a waterfall, the thick, white seed started to pool within her stretchy womb. Her belly, already slightly bulged from the precum before, grew exponentially, until the cyber-vixen could hardly wrap her arms and legs around her own cum-filled belly. “Leandra…Vesta…that’s amazing! What a test…oooh man…I’m gonna cum…I’m cumming! Yes!!” Shoryuu yelled out, his pleasured gasps echoing on the walls of the mostly empty laboratory, and as his seed poured in like a river, continuing to fill the confines of his cybernetic lover, all thoughts of running a proper test immediately left his mind. His only concern now was his own pleasure, and how perfect these two girls would be to fulfill that end. 
Thankfully for him, they seemed fully dedicated to that task.
Though she could still feel literal buckets of semen firing off inside of her, Leandra pulled off of her masters mythical mast and turned around, opting to test her oral capacities as well, all of her own accord. The cyber-vixen impressed Shoryuu all the more as her maw expanded to fit just barely around the head of his cock, and the next load of cum poured down her throat freely, adding to the round, bulging mass that was now her stomach. 
“The test looks successful, Shoryuu. I hope that I may be graced with the next test?” Vesta asked, displaying a further evolution of her knowledge of her own sexuality. Though she was unable to properly display emotions, Shoryuu could tell by now that the programming was working; Vesta was trying to act out of desire for a mate, rather than just because she was programmed to please. 
Finally having spent the first of his orgasms out completely, Shoryuu pulled his length free from Leandra’s maw, spilling some excess seed upon her bare breasts and tummy as he did. Even at three feet long, his cock barely reached Leandra’s maw anymore, as she’d become so filled with cum that she’d started to balloon out and up towards the ceiling. The extra space in the lab was filling up fast, and Shoryuu had a feeling it would all be used up before he was through. 
“Alright, Vesta…we can ‘test’ you next. Lay flat on your back on the floor, and spread your legs apart so that I may see your nethers,” Shoryuu instructed, his voice almost teasing and sarcastic as he mentioned testing. At this point, he could really care less about testing anything, and Vesta complied with a haste that was certainly unlike a machine to do. 
“Shoryuu…?”
It was Leandra, not Vesta, who called out to him.
“Yes, Leandra?”
The overstuffed cyber-vixen had leaned herself against the corner wall for support of her new mass, and was clearly adjusting well; she could just barely reach her arms around enough to stroke at the pleasure-slickened labia that rested between her legs. “Could you turn partially so that I might…’record’ your test data?”
She’s so turned on that she wants to watch. This is working even better than I expected! And she’s even fingering herself!!
“Good idea, Leandra. Vesta, turn with me so that Leandra can keep a watchful eye over us and record the trial data on your body,” Shoryuu ordered, and Vesta quickly complied. Shoryuu was sure that she would be grimacing with impatience at this point if she could express it, and he took something of a twisted enjoyment in that fact. He took far, far greater enjoyment in stuffing his cock, still stiff and throbbing from the heat of the moment, all the way into Vesta with a singular thrust. Her body didn’t even have to take the time to adjust, and the perfectly stretchy fiber that she was made of accommodated his cock so perfectly, it really did fit like a glove. 
Vesta closed her legs around Shoryuu’s back in an unbreakable vice, keeping him from pulling out of her anytime soon. His movements were even restricted by her powerful body, Vesta could force his hips into deep, quick thrusts. “You are a perfect fit for me, Shoryuu. Would you like to try further enhancement…?” Vesta asked, and even as robotic as her voice sounded, it seemed there was something of a gasp at the end, an inkling that Vesta truly was garnering pleasure from this.
Without warning, Shoryuu used his magic to increase the length of his cock another foot, and it grew even thicker, but Vesta’s stretchy body quickly adapted, and she fit around the growing, pulsing length like she was made him, and him alone. “I think that’s a great idea, Vesta…and you’re still so tight! Nngh…” Shoryuu gritted his fangs and grinned, his teeth shining pearly white in the lights of the laboratory. He couldn’t remember the last time he felt so much pleasure, perhaps, it was the most he’d ever felt in his entire life, and the best part was that he still wasn’t finished. Curious to see how Leandra was reacting, Shoryuu turned his glance away from Vesta, and what he saw confirmed that these girls couldn’t be just ordinary machines.
Leandra was grinning.
It wasn’t the kind of grin that he could have put into her programming, or the kind of grin she could have seen and then replicated, since she’d never seen any others yet. This was a knowing grin, that what she was doing was undoubtedly naughty, and yet, so very enjoyable. The amount of lubricant flowing from her netherlips increased appropriately with her arousal, until Shoryuu could hear a quiet schlick schlick schlick coming from the corner, and a deep, womanly panting that could make a porn star blush.
“I wish to see you fill Vesta, Shoryuu…somehow, I know that it would please me. I want to see you inflate her to the very edges of this room…while I finger my passage in pleasure. Ahhh…will you please, do that for me?”
Leandra’s encouragement was the perfect thing to keep Shoryuu derailed from treating this like a proper test, and treating it more like his fantasy come true. 
“Vesta, I think Leandra is taking a liking to you, and seeing you filled up like she is would make her feel even more pleasure. I hope you understand that you have no choice but to comply,” Shoryuu explained, as he turned back to look at Vesta once more, and he rammed into her folds with renewed vigor, his flesh meeting with her synthetic fibers with a loud, fleshy slap!
Vesta tightened her legs even further around Shoryuu and used her stretchy, flexible tail to flicker up and tease under his draconic tail, right near his tailhole, to add a new dimension to his pleasure. “I am not complying, Shoryuu. My body wishes to be filled, and to please you and Leandra. I want you to fuck and fill me, Shoryuu…please!”
That sense of desire and urgency was clearer now than ever in Vesta, and Shoryuu was spilling precum yet again. Whereas Leandra took a little while to form a bulge, Vesta’s body type was made with the expressed intent to show off bulges as much as possible, and as Shoryuu’s cock grew a little larger with each thrust, the head of his cock started to bulge out in Vesta’s stomach, stretching her body in ways that no organic female ever could, and the bulge remained and grew as slick, clear precum started to engulf her innards.
“You girls are lucky that I’m able to produce so much, or there wouldn’t be enough to go around…but you feel so damn good, Vesta, and Leandra watching makes it that much hotter…I’m gonna cum again any second, my dear cyber-wolf…get ready to clench me as tightly as you can!” Shoryuu instructed through a low, moaning voice, unable to even try to mask his pleasure, as he’d been told to by their creator. 
Vesta took to the feminine wiles that Leandra had already figured out, and brushed a few locks of Shoryuu’s hair away from his eyes so she could appreciate them more fully, treating him as a true lover, and not just as the thing that was fucking her. In her attempts to pleasure the dragon-demon, she replicated the thrusts of his hips, and found herself experiencing some gratification from it as well, so suddenly, she was bucking her ass hard against his hips, trying to milk his cock of all the cum that she could, without even manipulating her inner walls yet.
“Milk him dry, Vesta. I’m so wet just thinking about it, I can’t wait to see you blow up like a balloon!” Leandra moaned from the slight gap in the room, fingering at her slit furiously now, spilling lubricant all over the laboratory floor without care or concern for the mess that she was making. Watching the act seemed to turn Vesta on even more, as she finally took Shoryuu’s order and waited for the dragon-demon to hilt her, and the moment he was buried home, she squeezed as tightly as she could on the thick, wide head of his giant draconic cock. Leandra’s words in combination with that sudden, tight grasp were far more than Shoryuu could handle, who already felt lightheaded with pleasure, and now, a second orgasm in mere minutes was knocking at the proverbial door. 
Vesta felt the first burst, and her whole body seized up around Shoryuu. The entirety of her long-stretched vaginal passage clenched with an amazing strength, so tight that it robbed Shoryuu of his breath, and even of his voice, for a moment. “Is user Shoryuu not pleased? I feel like…like I may be cumming as well…” Vesta explained, as the mechanical part of her brain tried to reason with the ethereal mortality that seemed to fill her mind. Suddenly, she lost total control of her inner walls, and rather than a solid squeeze, her pussy quivered all over the length of Shoryuu’s cock, throwing him clean over the edge of a powerful orgasm.
“I…it…it feels incredible, Vesta…oh God…that’s so good…I’m cumming again already…fuck! Hold me tight, Vesta! I wanna fill you all the way!” Shoryuu proclaimed at the top of his lungs, finding his voice again in the form of an orgasmic howl. The dragon-demon felt his entire body tensing as his sack, having swollen even greater to accommodate his now melon-sized testes, squeezed around those same orbs of pleasure and forced from them a torrent of cum, splattering the insides of Vesta’s artificial body. The bulge that popped up from her stomach grew ever more, and suddenly, it was like a small mountain in the middle of her form, keeping her back pressed tight to the floor as she was pinned by the weight of it. 
Leandra was so turned on by the sight of Vesta starting to inflate that she brought one of her daintily furred paws to her maw and slurped the artificial lubricant off of it like it was nectar to be drank from the most delicious flower. Her moans had been drowned out by the show going on across from her, but she’d called out in delightful orgasm only moments earlier, heralded by a spray of lubricant that reached a few feet across the floor. Eagerly, she watched as Vesta continued to grow with every fresh pump of thick, sticky seed inside her womb and belly, to the point that she wondered if Vesta might burst…and that was the point of the test all along.
“I can’t believe I’m able to stretch so much, Shoryuu! Please, don’t stop filling me…test me to my very limits!” Vesta cried out, and for a moment, her voice sounded more organic than robotic. Shoryuu hardly had time to wonder about the change as he slammed his hips home again, excess seed splattering upon his crotch and spilling to the floor as each thrust gave gallons more of his essence to the massively inflated cyber-wolf. There was only one moment where Shoryuu was even slightly worried, as lost as he was in bliss, and that was the very moment that Vesta’s muzzle pressed right up to the ceiling, and suddenly, the enormity of the situation hit him, quite literally. 
“…Damn…I guess I got a little carried away there, huh?”
Shoryuu pulled out, his cock acting as the only thing to stop some of the excess seed from gushing out, and he found himself soaked in it, but even the slight leak did nothing to deter Vesta’s size. She nearly took up the whole corner of the lab by herself, and Leandra was completely marveled with the sight of it. 
“Indeed, but the test has yielded positive results, Shoryuu. I made sure to…record all of the data for you. I have to say that I quite enjoyed doing so,” Leandra said, rolling over onto her side so she could crawl closer to the dragon-demon. 
“I also find myself satisfied, Shoryuu,” replied Vesta, still a bit mechanical in her phrasing. “I hope that there will be more testing in the immediate future, for us?”
Shoryuu looked around him.
He saw the mess, both of extra lubricant that had sprayed along the floor, and cum that continued to leak out, as it surely would for the next few hours, maybe even days at this rate.
He saw the data in the computer, and that all of the tests had indeed been completed in a timely fashion and that there should be none left to run.
And then, finally, he looked at the two giant, cum-filled ladies on either side of him.
“As far as I’m concerned, ladies, the testing has just begun…”