On Buddy's planet, water had been a commodity, something that the rich got flown in and the poor were lucky to find. He'd been in the middle ground, just able to get enough to last a few weeks, but to still feel that overwhelming thirst that had plagued him and his family. Now though, on this station, there was plenty of water. He didn't know where it came from in space or how it was produced, but at the moment he didn't care.
For a couple of drinks on one of the lazier days at the base had made him quite parched. He stumbled into the bathroom, letting the door slide shut behind him, and leaned on the counter. A bubbly laugh managed to escape with a small hiccup and he glanced over the bathroom. He finds his target in no time, a grin crossing his scaly face as he heads over to the tub. 
Because the team here was so varied in species, the shower head was nothing more then an adjustable hose, with different heads that could be attached and plenty of length to reach any tough spot. The heads weren't important in the least to Buddy, and he twisted off the cap and started the flow of water. Just a few seconds of watching that crystal-clear and cool water flow before him had his mouth feeling like the deserts he'd lived on, and he shoves the hose into his mouth to savor the chilly drink. 
He shuts his eyes and rests back in the tub as he gulps down the water, the flow through his body one of the best parts. Swirling down through his stomach, along the tube in his spine, and collecting down in his tail. The thick, but narrower tail slowly begins to fill with cold water, and Buddy finds himself resting more and more on it, relaxing against his tail like the sloshy beanbag it was becoming. It was designed to stretch and store water for the long, grueling hot months on his planet, like a water reserve, as it only grew wider with the more water he greedily glugged. He knew he had more then enough strength to drag it back to his room if he needed to, and he keeps sucking down more and more, just letting his mind relax and give into an instinctual need to fill that thirst.
He could actually hear the sloshing behind him as his tail began to reach its maximum capacity, becoming firmer and almost rotund as he rested back against it. Surprisingly, instead of concerned, Buddy seemed almost oblivious to the state of his tail, as with no where else for the water to go, it began to back up the tube. Water was flowing into his stomach at a rapid pace. But in fact, this had been his plan from the very start. 
It felt incredibly good actually, rubbing a hand over his filling stomach and allowing himself to take bigger and bigger gulps of water. His normally toned stomach was becoming soft and squishy, similar to touching a water balloon. His hands clasped and rubbed at that cool, sloshy belly as it only kept growing with each swallow. Of course Buddy had never been very paitient. Slowly, he reached over, turning on the hot tap in combination, both hands quickly moving to keep the hose in place. His stomach gurgled, groaning against the higher fill and becoming rounder far more rapidly. 
His shirt began to grow tighter and tighter, straining. He perked up at the ripping sound from the fabric as it split up the middle, but he still didn't care. He had a new goal in mind-to see just how big he could get with water. His belly continued to gurgle and slosh, growing to start filling up the tub. He massaged it gingerly with his feet, the water leaking from the sides of his mouth. He could feel his stomach strain, the skin almost creaking as it thinned, and an ache became apparent over his round belly. 
Buddy's body had begun to stretch as his stomach kept growing, taking up room in his chest and forcing him to spread his legs apart, pants splitting up the middle. Thanks to the design of his skin though, to fit his tail, the rest of his body was just as stretchy. Even while it groaned and quivered, his belly could still go even further, bubbling like a cool spring. 
If there was something else he was though, it was stubborn. Steeling his resolve, he shoved the hose deeper down his throat so he no longer had to worry about swallowing, still curious about just how huge he could get. He shoved the stomachache into the back of his mind and rubbed his taut orb of a belly, squeezing his eyes shut and swallowing back water around the hose. 
It was becoming impossible to reach around himself now, his gut as big as it was. Nearly a five foot radius of cool, flowing water swirling into a big orb within him. The water was starting to fill up different parts of his body, fattening his limbs and neck up. It pressed up into his chin, squeezing his jaws shut, cheeks beginning to swell from the flow. He rubbed over his belly with his feet and hands wherever he could reach, a small part of his mind wondering if he may have gone too far yet...
His body was getting squeezed by the tub on all sides, skin creaking and thinning out, starting to become translucent enough to see all the water swirling within. The pressure was insane, and seemed centered all over his slowly growing form. His limbs had become bloated enough that they jutted out from his sides, no longer able to move them to rub over his tightening ball of a belly...or remove the hose for that matter. 
Realizing his error, he flailed, tried to call out for help, but with both of those options out of the picture, the only one he had left was to keep growing. And growing. And growing...His body was growing into a complete sphere, swallowing up his arms, legs, even his equally bloated tail. He was becoming huge, taking up a good chunk of the bathroom at this point. And it felt absolutely amazing.
Just hearing that slosh of water, his body creaking and groaning, and all that pressure swirling around in him was driving him to the brink of orgasm. He gurgled and moaned around the hose, cheeks swollen up around his head to the point where his face could be barely seen. At this point, he realized he didn't even care if he popped. It was worth it to feel this good...A deep, rumbling groan echoed through his frame, skin creaking like an overfilled balloon. His stomach was starting to strain, heaving and pushing for room. 
His skin struggled, shaking to keep together in some form, small leaks starting to pop up all over his overfilled body. Water gushed from his mouth around the hose, and each gulp was getting harder and harder to work down. Pain and pleasure wracked over his body, growing out just bare inches at this point. He whined, groaned, and burbled through each quake, each push his body gave as it neared its absolute limits. If anyone had walked in at that point, all they would see is one big scaly balloon, set to pop at any moment. 
He struggled to swallow down the last few bits. The first sloshed down, belly going rock hard. Solid as a boulder and straining to keep together, too full to even shake.
A second gulp took more effort, choking and panting through his nose. His belly pushed out, groaning. More leaks sprung up, and it felt like an enormous effort to hold it back. He moaned in ectasy, the pressure so immense, so powerful...
The third was a task all of its own, so set to burst at this point he couldn't force himself to swallow. It built up in his neck, flowing and swirling in on itself like a backed up pipe, as he clenched, panted, strained, and struggled to get that one, last gulp down into himself.  He gritted his teeth, struggling as he leaned his head back, took a deep breath through his nose and slowly started to force it all downwards. His belly heaved out one last time, groaning and shuddering, a thin creaking sound echoing out, before suddenly-
BLOOSH!!