My Dress-Up Darling's Burgeoning Backside

WARNING THIS STORY CONTAINS: Marin (My Dress-Up Darling) Butt Expansion

On her way to Gojo’s house to try out a new cosplay, Marin picks up a cup of gelato from a food stand. While she enjoys the treat, she’s left oblivious to the fact that her growing rear is making it difficult for Gojo to both put on her costume and avoid getting squashed.

This story was voted for and suggested by my Patrons.

---------------------------------------------------------------------------------------

   Taking a moment to catch his breath, Gojo ran his fingers through his short black hair as he took stock of the controlled chaos around him. Despite having done plenty of cosplays over the years, there was still quite a bit of mess left behind when it came to putting them together. The effects of this frantic rush to finish things could be seen in the form of cuts across his blue samue and pants. In direct contrast, the cosplays he had been working on were in pristine condition. The only thing left was to make the last adjustments needed to ensure they would be ready for the convention only a few days away. He wanted everything to be perfect, especially for the person who would be wearing them.

   Just as Gojo began to wonder why Marin was taking so long, he heard a ring at his door. Making his way down the stairs, he couldn’t help himself from lingering on her diminishing ability to show up on time. On multiple occasions she had been late for meet ups and sometimes even school due to her being distracted by food or something else that caught her interest. These errant thoughts left him concerned with how she would handle her third year finals in high school. Pushing his worries to the side for the sake of getting things done and enjoying the upcoming convention, he opened up the door.

   Marin stood before him wearing her school uniform: a white dress shirt, blue skirt, and navy blue tie. The uniform had been adjusted in several ways to fit her style, the more carefree look going well with her typically upbeat attitue. Waving at him with her glossy pink nails, she delayed an actual greeting as she pushed back her locks of blonde hair to move them out of the way of the treat in her hands.

   “What is that?” Gojo asked, pointing towards the cup containing a bright pink gelato.

   “A little snack,” she replied before swallowing a spoonful. “There was this stand I passed on the way here that was giving away free samples. Would you like to try some?”

   “I think I’ll pass for now,” he said, stepping aside to allow her to come in. “I don’t mean to sound rude, but don’t you think you should be careful with those?”

   “It’s fine,” she said as she swallowed another helping of gelato. “They claimed that the ingredients were made from all natural fruits. Besides, any weight I put on will be easily taken off walking around the convention this weekend. It’s not like little sweets here and there are going to stop me from cosplaying my favorite characters.”

   “While we’re on the subject,” Gojo said, following Marin upstairs into his room, “there are a few I need to make adjustments for.”

   “Which ones?” Marin said, scarfing down the rest of the gelato as she sat down on the edge of his bed.

   “Well to start, Lightning Lancer Lady,” Gojo said as he grabbed the outfit in question.

   Marin nearly choked on her gelato as she beheld the costume in Gojo’s hands. Everything from the shade of green adoring the jumpsuit to the bandolier of weapons across the chest were just as they looked in the show. Eyes gleaming as she beheld the silver wig styled into the shape of a lightning bolt, she looked about as excited as a kid in a candy store.

   “Gojo, this is perfect,” she said as he handed her the costume. “I absolutely love it.”

   “Thank you, but it’s not quite done,” Gojo said, beaming at her words of praise. “I still need to make sure it fits you.”

   “Say no more,” Marin said, putting her empty cup aside as she pulled down her skirt.

   Turning away his head at the last moment, a giggle from behind Gojo got him to turn back around to see her panties obscuring her lower half.

   “Still so bashful after everything else we’ve done?” Marin teased.

   Taking a deep breath to console himself, Gojo approached her. “Let’s just get to work on the costume,” he said, handing the pants over to Marin to try on.

   Getting up from the bed, Marin put both of her legs inside the pants and started to pull them up. The eager smile on her face that had come from the excitement of finally getting to wear the cosplay gradually began to disappear. Her more cheerful appearance was replaced with a furrowed brow and a look of annoyance as she continued to try and pull the pants up. Stomping her feet on the ground, she made her way to the center of the room as she attempted to get the clothing to fit.  Seeing the way she continued to struggle, Gojo let out a sigh that sounded like a parent being disappointed with their child.

   “Marin,” he said, holding the cup up to her face, “how many of these have you had?”

   “Just the one, I promise,” she replied as she tried over and over to get her pants up. “I might have indulged now and then, BUT I’ve made sure to balance it out with plenty of exercise. Not to mention working myself to near exhaustion with my modeling job to pay for all of this.”

   Gojo merely responded with a continued stare.

   “Okay, I promise I’ll lay off the junk food,” Marin said. “Now could you please help me?”

   Gojo nodded his head as he approached her and got down on his knees. “Alright then. Hold still and I’ll try to get these on so I can see where they need to be let out.”

   “You’re the best,” Marin replied, turning her happy expression back on like she had flipped a switch in her brain.

   Grasping the waistband, Gojo proceeded to slide them up her legs. Though he had done similar acts in the past for the sake of her costumes, there was still a stir in his body that got his heart racing from the mere act of touch. Trying not to stare too long at her panties or buttocks, he continued to pull until the material reached her waistline.

   Gojo’s slow ascent was stopped as he felt the fabric get stuck around the peak of Marin’s hips. Forced to actually look at what he was doing, he fought against any lingering feelings of awkwardness to try and get over whatever was blocking his way. Though it took a bit of effort and threats to rip the carefully crafted outfit asunder, he eventually managed to get the pants in place.

   “So, how do they feel?” Gojo asked.

   “A little tight,” Marin replied, barely able to sink a single finger inside of her pants. “On the other hand, it looks absolutely amazing.” Looking across to the full length mirror, she hazarded to strike a pose that the character used in the show. “I’m sure you can fix that little issue no problem in time for the convention.”

   “You can count on me. Stand still right there and let me go grab my-“

   Gojo paused as he watched his efforts be undone as the pants slipped down an inch from Marin’s waist. Letting out an annoyed huff, he grabbed the top once more and dragged it back into place. No sooner did he release the waistband from his fingertips did it defiantly go back down again. Repeating this over and over again, it was made quite clear that the pants weren’t going to stay in place anytime soon.

   “Marin,” Gojo said, pulling the pants up once more, “hold onto this.”

   “You got it,” she replied, tightly grasping the material.

   Rushing across the room, Gojo grabbed his tape measure and got back to his spot on the floor. Bringing the measure towards Marin’s backside, he paused as he felt that something was wrong. Pulling down the tape, he let his gaze linger on her lower body. A slight twitch preceded a small ripple going through her backside. Though she didn’t seem to notice, Gojo certainly did as he watched her rear gain an extra layer of fat to further strain the pants.

   “Marin are you feeling alright?” he asked, wincing as he watched her backside shudder again.

   “I feel a little tightness from the pants,” she replied, keeping up her grin as she remained blissfully unaware of the situation, “but it’s well worth it. Especially if the other cosplays are going to turn out this good.”

   Trying not to cause her any unneeded stress, Gojo tried to focus on the task at hand. Keeping the tape measure in place, he was surprised to see that her hips had already grown five inches over her original size. Holding onto the measure, he adjusted it as he watched her backside continue to expand. Surpassing 40 inches and moving past 45, her hips showed no signs of slowing. It was only upon his fingers struggling to keep the tape around her 50 inch hips did she realize something was wrong.

   “Um, Gojo,” Marin spoke, turning away from her reflection to look down at him. “What are you doing? I feel really weird. Maybe we should take off these pants and work on them later. I wouldn’t mind trying on the bikini for the…”

   Marin trailed off as she watched her lower body shudder. The added layer placed around her backside forced Gojo to release the tape from his grasp. The resulting wobble of her thickened rear shimmied down a portion of her pants to leave the edge of her underwear visible. Seeing a tremor precede another layer of growth, she clasped her face between her hands.

   “What’s going on with me? Is that real?”

   “I don’t know and… I really don’t know,” Gojo replied trying to keep himself calm for her sake. “Did anything weird happen to you today?”

   “No, nothing. I got off of my modeling shoot and came straight here.”

   An obvious omission in Marin’s story had Gojo momentarily turn away from her to grab the empty gelato cup. Looking back and trying to ignore the extra area of exposed butt cheeks, he lifted the container to his face and took a whiff.

   “What kind of flavor is this?” Gojo asked, holding the cup towards Marin.

   “They told me it was based off of some rare fruit in another country,” she answered. “I don’t remember what it was called, but it tasted good.”

   “Maybe you’re having an allergic reaction to whatever was in this. Let’s try and track down that food stand so that we can-“

   Gojo fell silent as the sound of tearing fabric echoed through the room. Turning his attention back towards the growing derriere, he was horrified to see a split in the seams. Watching the opening expand alongside her butt cheeks, he grasped at the waistline in an attempt to pull them off.

   “What are you doing now?” Marin asked, shuddering as Gojo tried to remove the cosplay piece.

   “I’m trying to get these off before they’re completely destroyed,” he answered, finding it even harder to remove the clothing then it was to squeeze them on. “After we’ve worked so hard on these, I’m not going to let our efforts go to waste.”

   Try as Gojo might, the fabric would not let go of Marin’s hips. Their stubbornness further strained the fabric as her lower body continued to swell with extra girth. Ignoring the perfectly plump bubble butt Marin had obtained in the process, Gojo continued to gently tug to avoid damaging the clothing any further. Unfortunately, he only realized that his efforts were in vain as he watched rips form across the entirety of the pants. One final surge of added thickness spelled the end for the garment.

   The green tights were tossed across the room in the wake of Marin’s thick ass cheeks surging with extra heft. Spitting out a mouthful of the material, Gojo’s disappointment about the loss of his hard work was quickly replaced by another feeling. With only her strained panties remaining around her hips, Marin’s larger backside was free to wobble around from the lingering ripples of her destroyed garment. Gojo took a deep breath, trying to fight against certain urges that came alongside him watching her butt cheeks jiggle around. It took several shouts from Marin to get him back to his senses.

   “Gojo, can you hear me?” she asked again. “I don’t know how much longer I can keep standing up like this.”

   Leaning his head back from Marin, Gojo now realized how far off her hips had grown from her body. She had easily doubled in width over the course of her growth. Considering that each of her butt cheeks had surpassed the size of a beach ball, it was shocking that the pants had been able to hold on for as long as they did. This extra girth unfortunately did not come with the balance needed to keep Marin from stumbling on her feet to remain upright.

   “W-what do you want me to do?” Gojo asked.

   “I don’t know!” Marin shouted out, understandably freaked out. “Just do something to keep me steady.”

   Acting without thinking, Gojo lunged forward to wrap his arms around her hips. The resulting squeak that left Marin’s lips was more than enough to inform him of the red blush spreading across her face. Though it was an awkward position, his tight grip on her thick rear seemed to do the trick in keeping her steady. At least at first.

   Gojo had to keep moving his arms back and forth as Marin’s lower body continued to expand. The speed of the growth had quickened, perhaps in response to her higher heart rate or in retaliation to Gojo’s hands trying to keep the extra flesh at bay. Regardless of the exact reason, the added layers being placed around her hindquarters gradually forced her butt cheeks to swallow up his head.

   Smooshed between the soft mounds, Gojo struggled to keep himself in place for her sake. Fingers slipping away from her widening hips, his hands gradually made their way backwards to grasp the edges of her thick buttocks. Sinking deeper and deeper into Marin’s crack, he frantically tried to think of a way to get out of the situation. While the obvious answer was to just let go, there was the lingering threat of having to look Marin in the eyes after getting so close to her private area.

   Gojo’s brainstorming hit a blockade as he felt a thin string slide against his forehead. Daring to shuffle his head around to look up, he noticed that what remained of Marin’s panties were stretched tight across the massive derriere. Though it was impressive that the garment had survived her growth spurts, it was clear that it wouldn’t be around much longer. His front row seat to the moment of the pair of panties’ destruction had the side effect of snapping the fabric against his forehead to force him to finally let go of Marin.

   Toppling backwards onto the ground, Gojo looked back up and watched at the impact of the destroyed undergarment sent ripples through Marin’s hindquarters. The jiggling sensation sent her pair of beanbag-chair sized buttocks into a shaking fit. The motion left Gojo in a sort of trance, finding it near impossible to look away from the swelling buttocks. This unfortunately left him unable to move as the weight overtook Marin’s balance and sent her falling on his face ass first.

   Slammed to the ground by Marin’s massive rear, Gojo was enveloped by the pudgy mass. Not a single ray of light could be see through the thick buttocks, leaving him to squirm in the dark. He stopped himself as he heard something akin to a moan leave Marin’s mouth. Another nudge elicited another strange grunt and got him to quickly revise his escape plan. Trying not to irritate her any further, he very carefully wriggled forward to plop his head out from beneath her cheeks.

   “Gojo, are you okay?” Marin asked, straining her neck to look past her backside to spot his face.

   “Yeah, I think so,” he replied. “Let me see if I can-“

   Gojo’s attempts to pull himself out were accompanied with more euphoric moans leaving Marin’s lips. Though she tried to keep her feelings at bay by chewing on her lip, there was only so much she could do in the wake of the sensitivity that came alongside her added size. Frazzled by the notion of what he was doing to her, Gojo stopped moving his body entirely as he tried to devise another plan.

   There wasn’t much time afforded to Gojo to think about the situation as Marin’s massive backside continued to expand. Under the threat of being suffocated by the encroaching mass, he pushed aside the worries of further provoking her as he wriggled backwards. Trying to ignore the resulting cries of pleasure as he squirmed around, he continued to pull himself out inch by inch. For just a moment he managed to free his torso from her hindquarters, but it was a very short lived victory.

   Marin’s ass cheeks began to rapidly swallow up everything in their path as they continued to grow. Given a moment to observe how each massive globe could contain a fully grown person, Gojo pushed himself to try to escape. While he could not fully escape from Marin’s encroaching butt, he did manage to climb up onto his bed and press his back up against the wall.

   Gojo was momentarily safe from being crushed, but the same thing could not be said for everything else in the room. The expansion of Marin’s hips led to the destruction of several pieces of furniture as they spread across the floor. Any of the cosplays that had been laid out to be tried on were swallowed up by the mass of flesh. Though at first Gojo was concerned if any of the props had managed to survive being squashed, his worry turned back towards himself as he felt her butt cheeks press against his face once more.

   Sliding his way up the wall into a standing position gave him just a moment to witness the gigantic ass that filled up most of the room. Straining to look over the hump of her backside, he could see Marin pressed up against the opposite side of the room. He could barely make out that she was clenching her fingers as she tried to suppress the shivers spreading through her lower body as her hips and ass grinded up against the four corners of the room. His view of her flushed face became obscured as her butt swelled to completely engulf his body. Surrounded on all sides by her ass cheeks and hearing the nearby wall straining to stay intact, he wondered how much longer he would be able to remain conscious.

   Gojo’s heart skipped a beat as he heard a cloud crack of wood. Wondering which wall would give out first, he tried to look around the room with what little visions was allowed to him by Marin’s hindquarters. Though he couldn’t see the crack, he could feel the draft coming up from the floor below. This was the only warning he got before he and Marin came crashing through the ceiling to land in the living room.

   The fall left Gojo once more pinned beneath Marin’s rear, but thankfully unharmed. The same could not be said for the remnants of his bed that had been crushed beneath her butt cheeks from the fall. The remnants of the coffee table were scattered across the ground, a result of it being flung into the wall when her hips slammed down on top of it. The lingering ripples of the crash were still shaking around her butt cheeks, the pair resembling a set of enormous wrecking balls of flesh. The single silver lining at the moment was that her massive backside had seemingly stopped growing.

   “Marin, are you alright?” Gojo called out.

   “Y-yeah,” she said, herself left immobilized as she balanced atop her massive hindquarters. “What about you?”

   “I’m fine,” Gojo said, trying and failing to free himself from her butt cheeks once more. “I think the couch took most of the force of the fall. At least what’s left of it. Let me try to slide out and I’ll-“

   “Please don’t move,” Marin pleaded. “I’m still a little sensitive there.”

   “Where?”

   “…everywhere,” she reluctantly admitted. “I lost my phone in the crash. Can you still reach yours?”

   “I think so, but it’s… stuck in a certain place.”

   Clenching her fingers, Marin took a deep breath. “Go ahead. Just make it quick.”

   Heeding her words, Gojo tried to very quicky retrieve his phone. Though he managed to grab the device without incident, the real issue came with trying to pull it out. Each tug sent another wave of stimulation through the gigantic rear to further torment Marin with strange pleasure. Trying to ignore the moans that parsed her lips, Gojo kept himself focused on the task at hand. Gritting his teeth, he gave one last hard pull to remove his phone and force Marin to let out a cry of pure euphoria.

   “Got it,” Gojo announced, holding the phone above his head. “Are you okay?”

   “Never… better,” Marin replied, letting out exasperated breaths.

   “I’ll go ahead and call someone to help us out,” Gojo said, already straining to push his fingers against the screen.

   “Before that would you mind… helping me finish?”

   Gojo paused, not quite sure what she meant with her words. Looking back towards her face, there was a certain look of wanting that made it clear that she was far from being tortured by his touch. Summoning up a boldness that the timid man rarely used, he took a deep breath. “Alright, but make sure you let me know if it becomes too much.”

   “Thank you. You can start by very gently-MMPPH!”

   Marin’s words were replaced with a hissing moan as Gojo brought his open palm down on her butt cheeks. Waiting for the ripples to dissipate, he repeated the motion over and over again. While one hand continued to smack the enormous globes, the other poked around her hindquarters to squeeze every inch of flesh that he could reach. These various provocations led to the expected result of Marin filling the room with cries of pleasure. Pushing himself through his own feelings of awkwardness, he managed to keep up the pattern long enough to feel her entire body shudder as she reached her peak. The resulting climax sent her entire body into the throws of ecstasy that threatened to swallow him up. Though he lost his phone in the ensuing chaos, he was left unharmed as she gradually settled down from the experience.

   Given a moment to stop and catch their breaths, Marin and Gojo were left to think over what they had just done. While Gojo pondered how they would discuss the act of bizarre intimacy they had just indulged in, he felt another shiver go through her backside. Bracing for the moment her ass would burst through the entire house, he was instead relieved to see her butt cheeks gradually starting to retreat from him.

   “I think that did it,” Gojo shouted out. “You’re shrinking down.”

   “That’s a relief,” Marin commented. “I don’t think there’s enough material in the world to make a cosplay to fit this kind of body.”

   “In any case, it looks like you should be back to normal in time for the convention,” Gojo said. “I’ll just have to rush to fix up the cosplays that managed to survive. Hopefully that gelato stand will be able to pay for the damages.”

   Marin fidgeted with her fingers for a bit. “Did you… enjoy this?”

   “What do you mean?”

   “If I could get my hands on more of that gelato, would you want to do this again?” Marin asked, putting on a slight smile as she said it.

   “I’ll, um, think about it,” Gojo said, momentarily hiding his face behind her receding rear, knowing full well that it would not be the last time he would get to experience Marin’s newfound kink.