CM: Fantasy Expansion Mansion

Series: Original Setting/Crossover with Goblin Slayer, RWBY, Highschool of the Dead, My Next Life as a Villainess

Characters: Cow Girl, Emerald, Shizuka, Katarina

Contains: Weight gain, expansion, tentacle sex, barely mobile, near bursting

Commission

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Dungeons were a dime a dozen. Some were remote, but others often had settlements built around or near them. The naturally occurring spaces were wellsprings of mana. They behaved like living beings, syphoning nearby ore deposits and morphing them into valuable treasure. Thus, adventurers would plunge into their depths for untold riches. Underground passages or other means allowed the areas to be filled with monsters. This created a lucrative cycle. Adventure, rewards, death. The dungeon fed itself, and adventurers gathered coin.

Occasionally, odd variants would arise. Dungeons that resembled natural caves or structures, dungeons that used other methods to feed instead of adventurers and vicious monsters. Either way, they always had treasure.

That was what guided four young female adventurers to the decrepit-looking mansion. It had appeared suddenly in a vacant spot near a trade route. It had been reported to the local guild, and these four had staked first claim.

Emerald walked slightly ahead, most of her tanned skin on display. An adventurer she might be, but her team had garishly revealing outfits. White leather shorts hugged plump hips and a rounded butt. Leather thigh-high boots squeezed equally thick legs so much that the supple flesh bulged around them. The only covering for her chest was a moss green piece of fabric. It did little to hold back her voluptuous, tanned breasts. They bounced with each step, heaving and jiggling as the rogue neared the mansion. 

Why did an adventurer wear such revealing clothes? Because it was enchanted. It had all the buffs a rogue would need, despite the nonexistent defense.

“I’m not seeing any signs of traps. Front door is unlocked, too.” Emerald said as she stepped on the porch. A gentle turn of the doorknob caused the large door to slowly open.

Cow Girl, the team’s barbarian, stepped inside. Her outfit looked like armor that had been trimmed into the shape of a bikini. Emerald’s top had been fabric, so it at least conformed to the shape of her breasts and gave them room. Cow Girl’s top instead squeezed hers. Bountiful cleavage bulged over the metal rims. They jiggled with each step and looked prime to pop free at any second. 

Like Emerald’s gear, Cow Girl’s armor provided little defense in exchange for many buffs. It allowed her curvaceous frame to swing a heavy battle axe as if it were a stick. She had been prepared to use the weapon to hack open locked doors, but the inside of the mansion had only open doorways. 

Emerald tested each and shook her head. “No traps or signs that a door used to be in any of these. I guess the dungeon doesn’t know what the inside of a mansion looks like.”

It wasn’t uncommon for dungeon structures to be a little nonsensical. Regardless, the next member of the party entered.

Katarina looked around. She practically sniffed the air as she looked around. “An untouched dungeon means all sorts of treasure! I’ll make enough to live eight lifetimes and eat like a queen!” The team’s witch had always been obsessed with prophecy. She raved about avoiding a doomed timeline. The entire ordeal made her more money-grubbing than the rest of the team. 

Her outfit was enchanted fabric with the least coverage of all. Straps crossed her chest in an X pattern, digging gently into her supple breasts. A triangle of material hardly cupped them, and their natural weight caused them to hang from the fabric cups. The bottom was practically four straps with a minuscule amount of fabric for her privates.

She was apparently a noble, so this outfit was especially obscene for her status…

“Be careful!” The last party member, Shizuka, exclaimed as she stumbled behind them. The klutzy blonde was the team's cleric. She was also the oldest member of the team. This caused her to fret and dote on her juniors constantly. 

Shizuka wore something that resembled a nun’s habit if it had been sheared to indecent levels. White fabric cupped her breasts with poor effectiveness. The largest breasts of the team bounced and jiggled even when she stood still. The faintest movement threw them into rigorous motion. She paid it no mind, though. She was too busy tripping over the black fabric that slid over her midsection and down into strips that nearly touched the floor. These strips of fabric weren’t sewn together. Instead, they hung freely. All shape was given by Shizuka’s curvaceous, plump body. 

The group had been organized at first, but Emerald’s claim of zero traps had Katarina in a frenzy. She looked into every room with reckless abandon until she spotted a chest. “Jackpot!” She cried in a sing-song voice. 

“Wait, you idiot!” Emerald exclaimed as she rushed into the same room. It was too late as Katarina opened a chest. Thankfully, it wasn’t trapped, and it instead held four rings. “Let me check those. They might be cursed-”

“She’s already wearing one.” Cow Girl sighed into her hand. Katarina was a handful even for her.

“Bad girl, Katarina!” Shizuka scolded, her cheeks puffed and adorable. “You shouldn’t put on strange rings you find in a dungeon! You have to use a spell to make sure they aren’t cursed and…o-oh.”

Katarina marveled at the golden ring and its blood-red jewel. The gemstone shone even in the faint light before the glow transferred to the witch’s body. It did not glow across her skin, though. The light instead seemed beneath her skin. It concentrated in her breasts, glowing warmly before her chest began to grow. Pale orbs of flesh swelled like water balloons. They rolled outward and quickly became as large as Katarina’s head. Bigger and bigger by the second, the pleasure was so intense that Katarina bit her lip and squished her thighs together.

That was when the party realized that Katarina’s thighs bulged with new thickness. They used to be dainty and petite, but now they were thicker than Emerald, Shizuka, and Cow Girl’s combined. Two fronts of fat pressed against each other as Katarina’s thighs thickened. Each leg trembled with pleasure as the glow spread into the witch’s hips. Those, too, thickened as her butt cheeks filled out into heavy lumps of blubber. They were bubbly, thick, and round. The little fabric that had covered them was now wedged between the meaty cheeks.

“Oooooh, this c-can’t be a cursed…feels toooooo good~” Katarina moaned as the growth slowly subsided. Her new curves tingled with sparks of pleasure. She slid her hands across her breasts and thighs, and the pleasure grew more intense. Even a breeze would drive her mad with ecstasy. 

Emerald looked in the chest and saw more rings. She didn’t hesitate to grab one and put it on. She had a passive ability that detected traps, and it hadn’t raised any alarms. The expensive-looking jewelry slipped over her ring finger before she felt a heat swell in her chest. She looked down and watched tan flesh bulge outward and sag with new weight.

Emerald’s thighs squeezed together by instinct. The heat rocked her core and blazed like a furnace. She moved a hand between her legs and rubbed as she felt her thighs swell and expand. She bit her lip and grinned as she relished this odd, magical item. 

Her shorts strained around her butt cheeks that raced to the size of basketballs. Every shift of her legs caused the cheeks to wobble and clap against each other. More fat built by the second, forcing tanned skin to roll over the waistband. This made it seem her shorts could burst at any second.

Emerald was brought to reality when she felt something touch her. Even as a rogue, she failed to notice Katarina appear in front of her. The witch had pressed her breasts to Emerald and began to squeeze even closer. Even covered by fabric, their nipples rubbed against each other. This sent bolts of pleasure down the pair’s spines. 

“These rings are the best” Katarina grinned lecherously as she reached around Emerald to grope the rogue’s butt cheeks. She squeezed as much fat as her hands could hold. The feeling of soft and still swelling blubber bulging between her fingers was quite exquisite

Emerald grunted under her breath. The pleasure was undeniable. She looped one arm around Kataraina’s back and pulled her closer. She roughly brought her other hand down on one butt cheek. The witch gasped in pleasure and surprise before Emerald began to grind on one of her thighs.

Cow Girl and Shizuka watched the display in surprise and slight envy. “Uh…” Cow Girl looked at Shizuka. “Any idea what’s up with them?”

Shizuka shook her head, clearing her thoughts. She raised her hands and activated her appraisal skill. A translucent screen appeared and displayed Emerald and Katarina’s stat pages. They weren’t under the influence of a curse or spirit. Instead, they were being buffed! Their stats had all increased by 25%. “My goodness! These rings are incredible.” She grabbed the last two and appraised them. “They gave so many buffs that their bodies had to expand to house them. All that energy must feel super tingly!” 

Shizuka was quite ditzy, but her explanation made sense…in a way. The most legendary of equipment often had a catch to it. Cow Girl thought of the stories she had heard before Shizuka slipped a ring on her finger. “Huh?” Cow Girl blushed as she saw the ring on her finger. The pleasure came a second later. Her metal armor creaked as her breasts rapidly ballooned. “Sh-Shizuka?!” She gasped before her face twisted in pleasure. Her expression at first was shocked, then it stalled. Her eyes became half-lidded, and her lips stretched tight. Then, she nervously held her hands over her crotch. 

Cow Girl’s thighs swelled and squished her fingers, but she only noticed the intense heat. It was the sheer, erotic warmth and excitement Cow Girl only had during certain dreams. One of her hands moved and groped a handful of her newly enlarged butt cheek. “O-ooooh~” Her expression relaxed as she moaned. She understood why Katarina had latched onto Emerald now. This pleasure was exquisite.

“See?” Shizuka cooed. “These are harmless. I think the added stats will help us even.” She giggled and put her ring on. She remained composed as her body began to tingle and glow. Her role as a priestess meant she was used to channeling external energy through her body. This ring’s energy had more bite to it, but she controlled it. Her breasts stretched the white fabric until it looked ready to burst. The black fabric that hung over her body was pushed aside by her hips and butt cheeks. Something about the exposed skin made Shizuka feel more excited. She looked at Cow Girl and giggled as the woman glared at her exposed skin. Shizuka opened her arms and beckoned the barbarian over.

Cow Girl had lost her inhibitions. She wrapped her powerful arms around Shizuka and buried her face between the woman’s breasts. Cow Girl shamelessly motor boated the fleshy fun bags as her thighs rubbed together with incredible force. She took deep breaths, smelling the lingering incense that clung to Shizuka’s clothes. That grounded her, but it didn’t stop her as she furiously groped Shizuka’s butt cheeks. This was the same grip she used on her axe (which now rested on the ground).

The party of adventurers was distracted by their shared expansion. They fondled and played with breasts and butt cheeks that were now as large as beach balls. The rings had made them stronger at the cost of abandoning concern. It seemed like they would spend the entire night in this room.

That was until a heavenly aroma reached them. Just a sniff hinted at savory meats, fresh bread, and hearty stews. Everyone stopped and looked at each other. Was this a trap? Perhaps. However, they were adventurers. Each retrieved their weapons and followed the direction of the scent.

A short trip down the hallway and deeper into the mansion revealed a large dining room. The center had a table covered end to end with food. Each plate, platter, and bowl pressed against another to the point that the table beneath was invisible. Steam wafted from most dishes as if they were freshly prepared. It seemed an obvious trap. Emerald was about to use a skill to test, and Shizuka had a miracle to detect poisons at the ready

Katarina had already picked up a dinner role before anyone could test if the room was safe. She bit into it before Cow Girl could stop her. “Oh my goodness!”

“You idiot!” Emerald groaned into her hand.

Cow Girl had started to shake Katarina by her shoulders. This was complicated by their recently enlarged assets. Their breasts noisily smacked together, and the spike of pleasure forced Cow Girl to release. 

Katarina hardly cared about any of this. “This bread is so fluffy! I don’t know how, but I think there’s butter inside, too. It’s simply divine!~” She exclaimed and ate the rest.

Shizuka waved a hand in front of Katarina as she chewed. “The food seems safe…perhaps this dungeon just wants people to visit? There are no traps, the rings only have positive enchantments, and this food does look delicious.” She rationalized with herself and nodded. “Yes, this must be a harmless, happy dungeon!”

Emerald and Cow Girl looked at each other skeptically. Yet again, Shizuka took initiative. She grabbed a cut of beef and a spoonful of stew. She stuffed the food into Emerald and Cow Girl’s mouths. The flavor was exquisite, certainly better than the rations they carried on adventures. Their will to resist and be skeptical withered away.

Cow Girl approached the table. “I know I’ll regret this, but it’s just like the cooking at home.” She lifted another spoonful of stew to her mouth and ate eagerly. “The last good food we had was at the inn a week ago…” She murmured through the mouthful. This food was so good by comparison that she almost cried. 

“I know, right! This is better than the quest reward by a million!” Katarina agreed. She had stuffed herself so much that her flat stomach curved outward into a rounded lump of fat. 

Shizuka and Emerald joined seconds later. Each girl had taken a side of the table, and they devoured the food before them. The food was indeed safe to eat, but the spells used to ascertain this only checked for poison. There was nothing to check for enchantments that made one keep eating.

It hardly took long for the entire group to sport rounded bellies. Those swelled and filled out until they began to soften. Everyone’s stomachs were still mostly round, though. The texture was revealed when the girls moved or leaned against the table. The fat jiggled and morphed around surfaces eagerly. 

They were all unaware of this, though. Their senses had been dulled by the rings and now were fully buried beneath their hunger. They stuffed themselves without any worry or concern, performing acts so gluttonous that it had never previously occurred to them. They cleared plates that could have fed multiple people, or drank soups and stews from their serving pots. The enchanted food caused them to gain weight more quickly than they should have. Their hips, breasts, butts, and thighs all swelled with preference, but their bellies raced to catch up. All of these curves softened as they stretched outward. Toned muscles were now buried beneath fat, and everything sagged with new weight.

Shizuka subtly noticed her new heaviness, but it only caused her to sit down. Her butt squished against the chair and rolled across the surface. Her stuffing eventually caused her hips to grow wide enough to roll over the sides of the chair. 

Everyone had obtained hips too large for a single chair. They stretched wider and increased in width and softness, helping to propagate butt cheeks wider than the chairs themselves. Still, none of this punctured the haze and flurry of food. They ate more and grew fatter, their minuscule outfits struggling to contain the rush of new mass. 

The group seemed like they’d continue to eat without end until a creaking noise sounded. Shizuka lifted her head, still chewing as she tried to listen closer. The creaking turned into a loud crack as the chair beneath her collapsed. Shizuka landed hard on her butt. The enlarged cheeks allowed her to bounce before she fell on her back. 

That distracted the group enough to stop eating. It only took a second to realize they had all gotten fat. Cow Girl and Emerald were shocked at their further expanded curves and weight. 

Katarina was mostly unfazed. The witch grabbed her belly, and fat bulged through her fingers. Her stomach was able to hang in front of her thighs, but it only protruded enough for a sliver to be seen beyond her breasts. 

Cow Girl grabbed at her arms and frowned. She couldn’t feel her muscles, no matter how hard she squeezed. Her underarms were as soft as pillows and jiggled with every move. “I knew this had to be a trap…”

Emerald was also shocked at her belly, but she was more shocked when she reached behind her. She groped her butt cheeks and groaned in frustration. Each cheek was massive, easily the fattest of the group. Her shorts had been obliterated, and the tanned cheeks were fully exposed. The fat was soft and morphed around her palms and fingers as she squeezed. She was too frustrated to speak. She just closed her eyes until something slipped into her mouth. Her eyes opened wide to see a large chicken breast. There was no hand holding it, and it squirmed almost as if alive. It forced itself past her lips and down her throat.

Katarina, Cow Girl, and Shizuka (from the floor) watched this. The chicken breast had floated from the table and fed itself to Emerald. Before anyone could react, the room began to glow. More food floated in the air and swirled like a hurricane. 

Cow Girl was ready to swing her axe at the food as it came closer, but two sticks of butter had split off. The butter rubbed itself along Cow Girl’s axe handle until she couldn’t maintain her grip. The axe clattered to the ground again, and food stuffed itself into Cow Girl’s mouth. She leaned back against the wall as another feast’s worth was forced into her belly. Her stomach swelled like a balloon, but it was still pure fat. Abs she used to possess were further obscured. Fat now rolled toward her knees, while her hips rushed to equal half her height. Her butt squished against the wall behind her, and her breasts bulged around her armor until it snapped. Bare breasts flopped free and rested atop her engorged belly.

Katarina had attempted to cast a spell. A burst of fire could have erased the food, but her mouth was stuffed before she could make the incantation. Her body rapidly fattened in the blink of an eye. Her belly hung lower, stretched wider, and became softer. Her breasts used her stomach as support after her top was destroyed. Seconds later, her scarcely covered lower half lost its only clothing. She was now completely naked and helpless against the swarm of food.

Shizuka hadn’t been able to get up from the floor. Her eyes were wide with shock, and her jaw worked to chew the constant stream of food. It hardly had to levitate to reach her. It flowed over the edge of the table like a river, and her body swelled across the floor. A full, rounded butt and back fat squished against the floor, pressed flat by her weight. The top of her habit tore away, and her breasts flopped lopsidedly against her belly. Already massive breasts somehow became more gargantuan. They became fatter, rounder, and they wobbled from the vibrations of Shizuka’s muffled protests. She didn’t kick or wave her arms, though. Her thighs swelled to twice their width, and her arms developed heavy bingo wings. All she could do was lie there and be fed.

At least the food was good.

These three had their efforts to fight removed, but Emerald had a different strategy. She chose to run. She turned so quickly that her butt cheeks and breasts swung from the momentum. Her thighs rubbed against each other as she pumped her legs to rush forward. It was hard to see as food obscured her vision. She felt her body bulge out with heavy, supple fat, but she knew she’d be fast enough to escape. 

Yet, Emerald stopped when she reached the door. Her hips had become too wide, and she was stuck. She tried to push harder, but she was completely wedged. Each second made the situation worse as her hips widened and fat spilled around the door frame. Her butt cheeks became larger and sagged under their weight. Bare cheeks wobbled chaotically as Emerald tried to struggle to no avail. Her breasts likewise flopped and smacked noisily against her flabby belly. She tried to grab the doorframe, but her arms were too bulky to bend the right way. She was entirely trapped.

Seeing as this was the only doorway, everyone else was trapped now, too.

That was when the glow of the room changed in color. It became a dull green as magic circles appeared on the floor. Katarina eyes these with anxious fear. ‘These are summoning circles,’ She thought. 

Tentacles began to emerge like writhing snakes. Their thinnest point was their tips, which were still wider than any of the girls’ wrists. They gradually thickened to the width of a forearm, while the base at the portals was as thick as the adventurers’ former waistlines. They were clearly powerful, and none of the women had the means to fight back.

The tentacles lunged first for Emerald.

“GMMFF!” Emerald groaned as she felt the tentacle plunge into her womanhood. It delved deeper and deeper as she bit her lower lip. Her legs had locked and began to spasm as the tentacle somehow managed to slip deeper. She felt another tease between her butt cheeks before it also began to explore her body. “F-fuuuck…” Emerald panted heavily as she felt her delicate areas being stretched. Just when she feared she could take it no longer, the tentacles retracted…

Only to thrust in again. Each tentacle had its own pace and rhythm, but both thrust in and out. Emerald’s body trembled and jiggled as she was fucked from behind. Her breath was shaky and uncoordinated as she moaned and grunted from the rough yet pleasurable experience. 

Emerald’s body felt more sensitive than it should have. The ring and enchanted food had enlarged her and altered her senses. Her body rocked back and forth, and the simple bounce and smack of her breasts on her belly and her belly on her thighs began to feel amazing. Her eyes crossed, and she started to drool. She never noticed that the food had stopped, replaced by a thirst tentacle that crept down her throat. 

The third tentacle focused more on discharging a sugary liquid down Emerald’s throat. Her belly filled rapidly and consistently like a balloon filled by a hose. Flesh bulged and rounded, tanned and shining from sweat. Soon, it touched the ground, and Emerald slowly rolled forward onto it. Her lower body was gradually propped into the air, more willing for the tentacles to fuck it. 

Emerald now seemed like a balloon. Most of her humanoid shape was filled out into a giant ball of flesh. Still, it had a feminine shape thanks to her breasts, hips, and butt cheeks. Her mind sank into bliss. All she wanted was more. More tentacles, more pleasure, more fat.

Emerald’s body swelled within the doorway until every inch of open space was filled by her. Unseen in the hallway, Emerald’s breasts grew larger and rounder until each was larger than a yoga ball. Her arms and legs filled in similar shapes until they were immobile spheres with her hands and feet protruding from them. Her butt cheeks thickened and wobbled erratically as the tentacles fucked her. Massive tanned blobs smacked noisily, drowning out her muffled moans. 

The rest of the team didn’t watch this in fear or concern. They were jealous. They wanted the same treatment. Thus, each woman stepped forward. The other tentacles turned toward them and moved closer. 

Katarina gulped in nervous excitement as a tentacle wrapped around her waist. It pulled her further to the center of the room and squeezed her. She was suddenly lifted into the air and tilted back. More tentacles grabbed her legs and spread them wide. Even then, her thighs were thick enough to squish together. Tentacles had to squeeze between the fat before they found her holes. They wasted no time and plunged in. Katarina threw her head back in sudden pleasure and moaned as she was pistoned in and out of. 

Shizuka had her hands bound together. She had struggled to get to her feet, but now she was tugged down onto her knees and belly. It was difficult to balance in the position, but her squirming ceased when a tentacle smacked her butt. She gasped just so a tentacle could plunge down her throat. She suckled on the flaccid thing as more wrapped around her hips and thighs. She subconsciously spread her legs before the tentacles crept deeper within her. Her lower body tensed as the new sensation assailed her. Every part of her felt more sensitive from her earlier growth, so it was impossible not to mewl in pleasure. Her body started to rock back and forth as the tentacles pumped into her. 

Cow Girl was likewise bound by the tentacles, though one grabbed her right wrist and another took her left ankle. The tentacles pulled in opposite directions so that she fell onto her side. The tentacle around her ankle hoisted the leg high before the tentacles plunged into her. Cow Girl bit her lip as she felt the tentacles push as deep as they could go. Her breath hitched in her throat as more tentacles teased her breasts and nipples. The appendages slipped between her cleavage and prodded at her nipples. That pleasure almost occupied her more than the heat in her lower body.

The entire adventuring party was now in the custody of the tentacles. Pleasure overtook all other senses, and growth resumed as the tentacles filled their prey. Rounded bellies bulged out further. They stretched and protruded in giant dome shapes, while once-toned backs were buried in fat rolls and mounds. Hips broadened and thickened until each woman was as wide as they were tall, but this added to their distended bellies to make them more spherical. Fat continued to pack thicker and jiggled in rolling waves as the tentacles continued to fuck and fill them. 

Somewhere in the haze of growth and pleasure, Cow Girl felt something strange in her breasts. They had become incredibly engorged, even compared to the others. Her nipples tingled before milk dribbled from them. Cow Girl cooed, and her eyes fluttered as milk continued to pour.

The tentacles took notice of this. They hoisted Katarina and Shizuka up and held them in front of Cow Girl. No coaxing was needed. The two girls latched onto Cow Girl’s breasts and began to suckle. They swallowed mouthfuls of milk, adding more fat to their already immobile bodies. This also drowned Cow Girl further in pleasure. 

The room was full of muffled moans and the slapping of fat as it wobbled and clashed. There was no escape from the tentacles, which seemed insatiable in their desire. The girls were drowning in their bodies just as much as they did in pleasure. There was no way they could move at this point. Their arms and legs were reduced to lumps of fat on their bloated bodies. Their bellies would touch the ground no matter how tall they stood, their breasts blocked any view in front of them, and their hips and asses were too wide for any of the doors in the manor. They were thoroughly trapped, but none seemed to care. They were hardly aware that their bodies neared their limits…

Emerald’s eyes crossed, and she groaned. The pleasure was so intense, but she felt she couldn’t grow any further. Her entire body felt tense, and she shuddered as she climaxed. Shizuka similarly felt her body writhe in orgasmic pleasure. She tried to think of a healing spell to ward off what she felt was an inevitable explosion, but she couldn’t. Katarina couldn’t think clearly enough to use a teleportation spell. She had resigned herself to the incredible pleasure. She didn’t care what happened next. Cow Girl didn’t think of anything. In the back of her mind, there might be some worry, but the pleasure between her legs and in her breasts was too much to contend with. She felt herself grow fuller and rounder as she climaxed and then…

Nothing.

The adventurers looked around. They were suddenly outside the mansion. It wasn’t as if they had never entered, though. Each could see they were still obese. It was as if they had still made it to the dining room and stuffed their faces, but the fullness from the tentacles was gone. 

“Oh my,” Shizuka blushed as she recalled the moments prior. She looked at Cow Girl, who blushed and turned away.

Emerald groped at her stomach and one butt cheek. Everything felt as real as it had inside the manor. She bit her lip and looked at the others. “One more round? There’s still plenty of rooms to explore.”

Katarina had already rushed through the door, and the others eagerly followed behind. Perhaps they would keep this dungeon to themselves a little longer…

THE END