Not today! Not like this!
These were the thoughts that raced through Lisa's mind as she heard the sound of her yoga pants split at the seams. For her, something like this was akin to the sound of gunfire in a church. Her day started rather normally, waking up in bed with her loving husband and getting ready to go on a morning jog. Her younger sister was about to get married next month, and planning was already heavily underway. She needed to get fitted for a new dress that afternoon, for goodness sake!
Yet here she was, in the middle of the park, with a hole in the butt of her yoga pants exposing her panties for all to see. This shouldn't be happening to her today! Her doctor told her that it could strike at any moment, but this was the last moment when she would have wanted this. It hung over her ever since that fateful doctor's visit, that pervasive and foreboding feeling of dread. Ever since she tested positive for Bouncerbutt syndrome...
Lisa thought back to last year when the disease became common enough to be newsworthy. Bouncerbutt syndrome... such a ridiculous name to call it but no one could come up with anything better so it ended up sticking. It tended to affect women past puberty, but it could also affect trans women provided they had a sufficient amount of estrogen. What it did was inflate a girl's butt until its weight forced her to fall onto it, where upon impact she would start bouncing like a child on a space hopper. There were also the mental changes, causing the infected to become a giggling mess obsessed with bouncing around on her enormous booty, as airheaded as a bimbo. There were other minor side effects, such as minor breast inflation and involuntary twerking, but the most prevalent side effect was rubberization of the skin. Those who exhibited the major symptoms came to be known as bouncerbutts themselves, a convenient term if a little degrading.
Most bouncerbutts couldn't even walk under their own power, due to both the largeness of their butts and the apparently euphoric feeling of bouncing around. Besides, most of the ones who could didn't want to walk because of the euphoria. It was hard to go anywhere lately without hearing the giggle of a bouncerbutt and the bouncing of two gelatinous butt cheeks constantly slamming on the ground. It felt like a recent trend, but in reality it had been going on for almost a couple years now. Only recently had it reached a point where the condition was common knowledge.
Lisa could practically feel her ass straining against her pants by this point, and already her gluteus muscles were involuntarily jiggling her buns. There was no semblance of rhythm to it, just an unending motion that built up in her rump that she couldn't fight against. It was happening to her all so fast! She had to get out of there before the rest of her changes took hold, even as she could feel her sports bra getting tighter as her lady lumps began to swell. What was she going to tell her husband? Or her sister? She ran as quickly as she could, even as her body was starting to protest.
Eventually the tightening in her chest forced her to stop. She leaned her hand against a park bench to catch her breath. Already she was having trouble keeping down the giggles that were bubbling up inside her gut. Her grip on the bench tightened until her knuckles turned white. She could feel the corners of her mouth tingle as a smile threatened to break out across her face. She could feel the urges building up in her legs as the undulating jiggling of her ass began to feel overwhelming. By this point her butt was already quadruple its previous size, and the hole in her pants had long since widened to the point that her whole booty was exposed. The more her booty shook, with an increasing amount of mass to shimmy, the worse the inclination to smile became.
It wasn't like becoming a bouncerbutt was a death sentence, nor were you considered too much less of a person. Then again, it wasn't like they had the best reputation either, since their minds became so absorbed with the desire to bounce on their derrieres like they had a report to file on Monday. Lisa remembered when two of her coworkers turned into bouncerbutts. They received pension for life and were now living comfortably, but they required assistance with certain things because of their condition. They retained most of their memories, and they certainly seemed much happier overall. Maybe... maybe she could find herself enjoying the rest of her life as a bouncerbutt.
Her butt cheeks continued to bloat and to jiggle, and Lisa noticed that her thighs were starting to become a part of their mass. Whatever size she would end up would become her new normal, and she would be stuck with it for the foreseeable future. They hadn't figured out a way to reverse the process yet, if they ever would. When there were so many worse problems out there, getting turned into a constantly-bouncing, big-bottomed, happy, jiggly bombshell was not high on a list of medical priorities. Bombshell was right, as her sports bra finally gave up its valiant efforts and broke apart. Her breasts, while not as big or growing as fast as her ass, were nothing to sneeze at. At least these finally stopped growing once they reached the size of small watermelons. With one arm she struggled to keep her engorged breasts covered.
She wasn't sure how huge she'd end up. The biggest one she'd seen had an ass so massive that their bounces were barely an inch off of the ground. Most didn't get nearly that size. Lisa could feel the bouncing and twerking growing more intense as her booty continued to swell. She felt more and more like smiling and laughing, a feeling that was harder to suppress the bigger her ass became. She grunted, feeling the growing weight of her hindquarters try to bring her to the ground. At the same time, she felt the very nature of her booty changing. It was soft, and doughy, compared to the flat barely-there derriere it used to be. Apart from that, the texture changed. Her cheeks became perfectly round, and slightly shiny, looking like huge rubber bouncy balls. Soon her thighs would become more booty flesh, and she could even feel her calves fattening a tiny bit.
The bouncing and jiggling continued as her butt cheeks started looking like a pair of meaty beach balls. As much as she hated to admit it, the feeling of each sphere wobbling up and down enticed her, and was dangerously enjoyable. Her knees buckled to the force of her uncontrollable twerking, as her hips got more of a workout in the last few minutes than they did in a month. She felt another titter slip out of her lips, and tried to steady herself. She just had to avoid bouncing, how hard could that be? She'd heard tell of a girl who held on for hours before she caved in and became just another bouncerbutt. She could do it! She knew she could! Right?
Her grip on the bench was weakening, and her breasts were threatening to slip out of her arm from the force of her booty's bouncing. Worse yet, people were starting to stare. Most of them were aware of what was going on, but that didn't stop them from watching. It was like a nasty car accident. Mothers averted their children's gaze and glared disapprovingly at her. A few quickly pulled out their phones, ready to dial the number of the support crew hotline in case her condition reached its final stages. By this point, enough people had witnessed the birth of a new bouncerbutt that plenty of protocols were put into action, like the support crew, whose job was to help new bouncerbutts settle and adjust to their new way of life.
The second her butt cheeks reached yoga ball size, Lisa lost her grip on the bench and the weight of her butt made her finally fall backwards. It felt like she was falling in slow motion, and she swore she could hear Piano Concerto No. 21 as she fell. She tried desperately to reach out, to grab something to stop her fall, but her rump landed on the floor before she could, and Lisa found herself bouncing several inches into the air. Her pupils swiftly dilated as she savored that brief moment of being airborne, before her hind end bounced on the ground once more. The newborn bouncerbutt wound up in the air again as a huge grin came to her face.
She forgot immediately why she'd been denying herself this joy, this euphoria. She giggled gleefully, tittering like a schoolgirl, enjoying the alien sensation of her booty sending her up in the air. Her head felt light as she forgot about her past worries for the moment, reveling in the newfound high of being a bouncerbutt. For the other people watching though, it wasn't exactly something new to them. Maybe not everyone had seen the birth of a bouncerbutt in person, but it was commonplace enough that they stared for a few seconds before moving on. The people who had their phone out dialed immediately and hung around to make sure the poor girl didn't hurt herself.
"Heeheehee! Boingy, boingy, boingy," Lisa absentmindedly giggled as she started bouncing around the park. It was a feeling unlike anything she'd ever felt before. The heavy feeling of her butt smacking against the ground over and over sent jolts of excitement up her spine that made her want to bounce around even more. It felt so amazing that she just couldn't stop laughing, and the smile on her face was evidence of such. She was fully beginning to embrace her new means of locomotion, with the bouncing several inches into the air at a time and the meaty smack when her cheeks landed only to spring her back into the air. She wondered how high she could bounce, wondered it she could touch the clouds where her head was going. Her humongous butt was large enough that even if she stood, it looked big enough to reach her ankles, meaning she definitely wouldn't be one of the few who could stand under her own power.
Soon though, the initial excitement of bouncing would wear off, and Lisa would return to most of her senses. She still giggled cheerfully and the smile wasn't going anywhere soon, but she'd calmed down enough to stop and rest for a second. She remembered her husband waiting for her back at the apartment. Wouldn't he be surprised to see what had she'd become. She hoped he would love how big her booty had gotten. She certainly loved how bouncy it was now she was just another bouncerbutt.