Momo was humming along the hallway, furtively glancing at Izuku as he carried their souvenirs. After deciding on their impromptu getaway together, the two had spent several days of quality alone time touring the city and enjoying the hotel's many luxuries.

As another bonus, Momo had stopped putting up her hair in its spiky ponytail. Izuku realized he could only count the number of times he'd seen her without it outside of sex on one hand. When he asked her why, she just said she wanted a change.

Not that he was complaining. He secretly felt Momo's true beauty only shone with her raven locks cascading down her back. Although she did reiterate she'd do it up again for whenever she donned her costume to keep it out of the way of her quirk. And, Izuku speculated, because it made her look stronger.

Clicking open the door to the master bedroom, Izuku planted the bag on the dresser and began unloosening his belt buckle when he noticed Momo standing still. She was in shock.

Following her gaze, Izuku's eyes bulged to the size of dinner plates when he saw Kyoka, newly enhanced with a far larger bust than last time he'd seen her, on the bed in a loose-fitting pair of overalls. One of her breasts peaked out, nipple erect and pointing outward.

"Mmm… hey Yaomomo, Izuku." She began giggling, biting her fingernail. The sultry look in her eye was clouded by lust.

"Kyoka. You… undertook the procedure?"

"Yeah…"

Momo took over for Izuku. "And you're now… you're now…"

"Got boobs on par with you other titty monsters, yeah." Kyoka proudly hefted up her bosom, letting it fall with a loud smack. She ground her butt into the mattress, wide hips pressing against the side of the overalls. Something dawned on Izuku.

"Where's Mei?"

"Ohhhh, Mei. Yeah. Me and Itsuka-sweetie showed her a lot of appreciation. Man she's got a great ass. Speaking of, Itsuka's got a ripe ol' booty too now. Should've seen her struggle to get into her panties, she's so big now. Here—"

Kyoka grabbed her butt.

"And especially here. Momo size and then some!"

She groped her boobs again.

"She made a beeline for Ochako. Man, she's such a lucky girl to be getting with all that thickness…"

"Ocha?" Izuku frowned. "Kyoka, what exactly is she gonna be doing?"

"Sexy times, pffft!" Kyoka blew a raspberry and flopped back onto the bed. As she begun drooling and staring vacantly into space, Izuku and Momo looked at each other in alarm.

"She's clearly not in her right mind," Momo said.

"Mei said the procedure was safe, but it's like she's hopped up on drugs."

"An apt comparison," came a familiar voice behind them. Stumbling down the hall was Mei, looking decidedly dishevelled with her hair messier than usual. She was sweating, but Izuku had a feeling it wasn't from work. She was also dragging her bra behind her like a spoil of war, not bothering to have put it back on after whatever happened.

"What did you do?" Izuku demanded.

Mei winced, visibly hurt. "S-sorry. It's my fault."

Sighing, Izuku hugged Mei close and gave her a peck on the lips. "No, I'm sorry. I'm just worried, okay? I'm not mad at you. We need to know what's going on."

Mei blushed, clearing her throat. "So in the process of upgrading Kyoka and Itsuka while you guys were away, I might've… put their sex drives into turbo mode without meaning to."

"So…?"

"It's like they're on the world's most potent aphrodisiac. It's nothing lethal, but they're going to be relentlessly horny for a short while. For anybody who strikes their fancy."

Mei paused, blushing again. "Damn, I guess when I put it that way what they did was kind of flattering…"

"Ohhhh, Hatsumeeeee!" Kyoka drawled from the room. "Is that you? Up for round two?"

Mei shrugged at Izuku and Momo's incredulous looks. "The ladies love me."

"How long are they gonna be like this?" Momo asked.

"I mean, it depends on a lot of things. Constitution, body mass, blood type—"

Mei stopped seeing how desperate Izuku and Momo looked. "I don't know guys, best idea I've got is to fuck her for as long as possible! I mean, you and Ochako went at it for something like four days, right?"

Izuku was taken aback by the suggestion. "Well yeah, but…"

"It's either that or she masturbates by herself. Sex is more pleasurable when done right, and you two are masters at that. Show her a good time and she'll be back to normal in no time… I think."

Momo sighed. "It is the only way, I suppose, crude as it may be. Still…"

Her eyes flashed at Kyoka's new body. "They're so perky now…"

As Momo self-consciously hoisted up her own breasts, Izuku asked Mei one final question.

"So Itsuka…"

"Is going after Ochako now, yep. I'm gonna check in on them. Wanna come with?"

Izuku imagined walking in on his girlfriends going at it, especially now that Itsuka was "Momo-sized" now as Kyoka put it. His pants grew especially tight… but he knew Ochako was able to handle it while Momo would need help with Kyoka. In fact, she was the only other one in the house who could handle an indefinite period of sex.

Reluctantly, Izuku shook his head.

"If you wanna watch, don't worry."

Mei leaned in to whisper sultrily into his ear. "I've set up the cameras so that they record eeeeevery last bit of action. You guys gave me your permission, after all!"

Mei giggled as Izuku blushed even harder. He wrapped her up in his arms and planted a wet, loving kiss on her lips. She panted as he retreated, biting at his lips.

"I really love you," Izuku said, massaging her butt.

"Same, big guy… but I guess we'll have to put this on hold." She nodded toward the bedroom.

Izuku walked in. "See you later!"

Shutting the door behind him, he turned around to see Momo stripping down to her underwear. Kyoka grabbed her breasts again.

"Hey Momo. Know how I love motorboating? Wanna try it?"

She shook her breasts enticingly. Despite herself, Momo was clearly taken by her new curves. Momo looked at Izuku for permission and he nodded.

"Guess it's going to take the both of us to calm her down," Momo surmised.

"Threesome huh? I can work with that." Izuku grinned.

She then dove onto the bed and pulled down Kyoka's overalls, stuffing her face inside her cleavage.

Kyoka gasped as she held Momo to her chest, relishing how Momo buried herself into her cleavage. They were quite large. So large, in fact, all of Momo's face was obscured from view as she enjoyed the new bountiful field brought about by Mei's mad science.

Reaching her hand for Izuku, Kyoka panted as Momo massaged her breasts around her face, her motorboating increasing in ferocity. The image of the two girls was too much for Izuku to take and he stripped in a flash.

On the bed in his boxers, Izuku claimed Kyoka's lips while slyly reaching down to her new bottom. He smacked it, watching how it jiggled and groping it. Kyoka could only squeal and moan into Izuku's mouth at the double pleasure.

Izuku noticed Momo also trailing her hands up and down Kyoka's body, savoring each of her expanded curves as if trying to imprint the shape of her body into her muscle memory. There was no sign a procedure had even been done on her. It was everything Mei had promised and more.

Izuku pulled away. His penis had been twitching ever since Mei informed him there was no real danger, and now, he was beginning to see the benefits of this. If this extended into a full day of sex with Kyoka, he wouldn't mind… he wouldn't mind that one bit.

"Okay, give me a second to—EEP!"

Momo had tried to pull away, but Kyoka pulled her down until they were face to face. Their breasts had smushed tight against each other.

"You feel that? My big boobs against yours? All the possibilities when combined with your mega milkers." Kyoka began moving, drawing Momo and Izuku's attention to their double cleavage. Kyoka raised her knee, bumping against Momo's core and making her gasp.

"What do you think of my new body?" Kyoka licked her lips.

Momo held her face. "Kyoka, you don't get it."

"It wasn't your body we loved. It was you," Izuku said, holding her hand. Kyoka blushed.

"Are you sure you're not going to regret this?" Momo asked.

Kyoka nodded. "Positive."

Momo sighed. "Okay. In that case…"

Momo framed Kyoka's face carefully, looking at her lustfully. She then flipped around so that Kyoka was on top of her, Izuku lined up behind her. Kyoka began panting, seeing what was about to happen. Her earphone jacks fell down beside Momo's face.

"Ready?" Izuku asked.

Momo licked her lips, groping Kyoka's breast. Kyoka moaned.

"She's so cute, isn't she," Momo purred. Then she pulled her down and they were making out, hot and heavy with their tongues.

Once Momo began making out with her, Izuku took that as a signal to go and entered Kyoka from behind. She was still extremely tight, just the way he liked it. If not tighter. Grabbing her newly expanded love handles, he began thrusting with his usual vigor, eagerly watching his girlfriends make out with each other.

Izuku swatted Kyoka's butt. The jiggle truly was fascinating, and the little moans it would earn him from her hotter still, interspersed with the ones from Momo groping her every curve. Her breasts shook back and forth from the force of his thrusts, each going deeper than the last.

Bending over so his chest lay on her back, Izuku took turns with Momo groping Kyoka's new breasts which Kyoka was clearly a big fan of. It made sense, considering how breast obsessed she was.

Izuku was further aroused as he traced her musculature. It had taken a while for him to register, since things had moved so fast, but Kyoka had bigger muscles from the procedure. Her strength had been enhanced too, but it was a mere fraction of the old version of the procedure Shigaraki had undergone. Her six-pack abs were rock solid, and her arms and legs felt truly powerful. But he had a feeling he couldn't test out her true endurance while having to worry about Momo…

Putting it out of his mind for now, Izuku put his entire body into his thrusts, kissing Kyoka's neck. Kyoka broke away from kissing Momo for air, eyes rolling back from the pleasure. Momo grabbed her breasts and began sucking on them like a newborn babe, making Kyoka squeal even harder.

Their motion went back and forth, Kyoka trapped in the middle of a cycle of pleasure. Izuku's thick, searing cock exploring her depths, Momo lavishing her gorgeous tits with her mouth. It wasn't long until Kyoka and Izuku came, screaming.

As cum leaked out of Kyoka and she flopped to the bed, Momo and Izuku lay on either side of her.

"I think that might've worked!" Momo said peppily.

Their sense of victory was short lived, however, as Kyoka suddenly sprang up like a woman possessed. She lunged at Momo and before they knew what was going on, Kyoka had pressed her mouth promptly against Momo's quim and began furiously eating her out.

Izuku could only watch in stunned silence as Momo was left to cling tightly to the bed sheets. Kyoka, expert at cunnilingus that she was, swiftly unspooled all of Momo's composure with just her tongue and the right little movements with her jaw.

Digging in as if it were a five-star meal, Kyoka moaned with glee as she gulped down Momo's juices. She held a death grip on her thighs and kept licking and licking until Momo exploded. Kyoka eagerly drank all of her ejaculate as Momo lay against the pillow in shock.

Kyoka rubbed her mouth, breathing heavily and already trailing up toward Izuku. She sat in his lap and began grinding against his thigh, licking at his tongue. She was closer to a dog in heat than a rational human being, especially with how she was humping Izuku's leg.

"I've got a feeling we've barely scratched the surface," Izuku said. He took over, letting Momo rest as he pinned Kyoka to the bed in traditional missionary style. If it ain't broke, don't fix it.

Izuku didn't pull out any of his major moves just yet. He settled Kyoka into a prone bone after their next climax and played with her butt. He had to think. Depending on how long this was, it might mean an extra day of no hero work. He'd have to put in double time… but mostly he was worried about how Momo would keep up.

"Is she getting tired?" Momo asked.

"No, she feels strong as ever. If anything she's getting more delirious. And the procedure enhanced her physical strength as well… we're going to be at this a while."

"Nothing for it then. I'm going to stay with both of you until this is finished." Momo massaged Izuku's shoulder.

"You sure?"

"Wouldn't miss this for the world."

"Alright then… Let's change strategies a little."

Kyoka was drooling into the sheets, eyes vacant as she gripped them tightly. With a few more decisive pushes Izuku ejaculated inside of her and she wailed. She was left panting, cum oozing out of her as Momo sat on Izuku's lap without reprieve. She rubbed his chest.

"The excitement might end up too much for her…"

"Sure you can take it?"

"I'm gonna be taking you for eternity mister."

Izuku hummed, pinching Momo's tush as she ground against his lap. Kyoka was stirring, meaning they'd be able to grab her attention.

Izuku held Momo close, depositing her onto his cock. He pressed his face into her bosom as he began softly bouncing her up and down. Delectable curves jostling with every movement. Izuku sucked a nipple, making Momo giggle in pleasure.

Kyoka had roused herself fully. "No fair…"

Crawling over, she tried squirming her way in. Just wanting to be a part of the heat, the passion. The love.

Izuku gave a naughty bite to Momo's nipple, making her squeal, and then eagerly accepted Kyoka's lips trying to butt in. Their kissing caught Momo's attention, who then brought her face down.

Izuku wasn't entirely sure of whose tongues and lips were rubbing against whose. But making out with two women at the same time was a delightfully depraved sensation. Especially as he heard their moans at every contact.

Momo pulled away eventually, but not with one last slurp against Izuku and Kyoka's tongues, leaving the two to continue making out with each other. Izuku rode Momo faster and faster, groping a breast as she giggled.

Izuku thought the tears of arousal dripping down her cheeks as she came was one of the hottest things he'd ever seen.

"Hold on, there's something I've wanted to try forever now," Kyoka giggled, pulling Momo off, and depositing her new breasts around Izuku's penis.

"Splendid idea, Kyoka," Momo approved. She sank down to meet her, and their breasts began touching. Nipple to nipple.

"Big tits are the fucking best," Kyoka purred. Then she began rubbing her mammaries up and down, with Momo following suit rubbing against each other and Izuku's dick.

Moaning, Izuku threw his head back. It was his turn to grip the sheets. He'd be lying if he said this wasn't a particular weakness of his. He looked back down long enough to see Momo and Kyoka reach down, tongues outstretched!

"AH!" They had begun licking his tip, large breasts doing the work stroking his shaft and then topping it off with lavishing the crown.

Izuku put his hand behind both of their heads, urging them on. Momo and Kyoka were moaning, their guttural sounds of passion causing the heat inside him to rise to new levels. Watching them lavish his penis, tits working overtime. It wasn't long before he spurted and came right on their faces.

"It's like a geyser," Kyoka remarked, licking up the stuff. Soon she and Momo were licking Izuku's cum off each other's faces, nipping at each other's lips all the while. When they were done, they turned back to Izuku with want.

"What next master," Momo asked.

"Roleplay, huh? I'm into it. You have two busty babes at your service honey. All. Night. Long." Kyoka licked her fingers. He'd seen her horny before, but there was a new hunger in her eyes that was making him melt.

"Alright… let's try something a little similar but a little different."

Izuku had Momo and Kyoka line up at his crotch again, but this time, their pussies squished his rod between them. He shuddered at the sensation.

"A little awkward, but I like it," Kyoka said. She was the first to start grinding against Izuku's shaft, and Momo followed suit upon feeling the push back.

Izuku's cock pulsed in between the heavenly cores of Momo and Kyoka. What made it all the more intense was when they began rubbing their wetness up and down his shaft, making Izuku moan.

"That extra pressure is doing you good, huh Master?" Momo moaned.

"Master, how's our super delicious pussies against your giant dick? Wanna plow us again? We'll let you do it for the rest of our lives." Kyoka followed it up with a particularly strong grind, giggling at Izuku moaning in response."

"We're your servants foreverrrrrrr!" The two sang out at the same time, and this was the final straw. Izuku ejaculated, semen shooting up in an arc over the bed. After a few seconds he was done, but Momo and Kyoka were delighted to be showered in it.

Izuku sat up, inhaling both of their lips. They pressed their luscious bodies against his for good measure.

"What's next?" Kyoka asked. Momo instinctively popped out several dildos, a couple of them strap-ons.

"I've had a little fantasy for a while…" She admitted.

Soon enough, Izuku was standing with Momo lifted up in a carrying position… with Kyoka lubing up a large strap-on dildo behind her.

"Ready?" Izuku asked.

"Do it…"

"I didn't hear you."

"Fucking do it already!" Something about hearing Momo—who was prim, proper, and high-class—break down and beg to be fucked by both her paramours was beyond enticing.

"Yaomomo, you are in a league of your own," Kyoka wisecracked. Then she and Izuku entered her from the back and the front respectively. Momo moaned as they began pumping, working her up and down.

The night passed by in a blur. They'd long since given up looking at the time. As heroes, they were already at their physical peaks, and Kyoka becoming even stronger through the procedure beckoned them to new heights.

Even through being pressed against the wall by Izuku, and then suckling on Momo's nipples while Izuku took breaks. The heat of her skin. The bottomless lust in her eyes. The fire she held for both Izuku and Momo. Never ending, never ceasing.

Lamps and tables fell to the floor. Towels and blankets. Drawers torn out in the frenzy of Izuku's orgasms, holding Momo and Kyoka tight to him as they rode out their pleasure.

It was one of the best nights of Izuku's life.

Izuku took a break first, letting Momo and Kyoka get a little solo time in since he'd been doing the lion's share of the work. When he woke up it was light out, but he didn't pay attention to that.

Momo was slowly pressing Kyoka into the bed, her doggy style pushing Kyoka's cheek into the mattress. She held Kyoka's arms behind her for greater leverage, taking a page out of his book. Both of their breasts jiggled hard with how ferociously they were going about it.

"Ungh, ungh, ungh, UNGGGGGH!"

Momo came, wearing the sensory dildo Mei had created. She fell back in exhaustion, letting Kyoka crawl up Izuku's body. After a full night of sex, she still hadn't had enough. Izuku was worried about what the other, stronger members of the harem would be like once undertaking this procedure.

"Come on big guy… let's go."

But Kyoka's eagerness to hop on Izuku's penis wouldn't be met just yet. Izuku had to focus on draining her sexual appetite first. He kissed down her stomach, slurping at her belly button and relishing her abs. Kyoka moaned, especially when Izuku's mouth found her pussy.

Licking adventurously, Izuku pressed his full face against her core. He groped at her breast, pressing the nipple between two of his fingers. She shrieked, spurting up in his face.

Coming up, he buried himself right in her chest. The smell of sweat felt so… Kyoka to him. And it's what made him extremely joyous to begin motorboating her.

"S-stop, it tickles!" Kyoka was giggling as Izuku blew raspberries against her chest, screaming in pleasure at his enthusiasm in between. Izuku sucked on one of her nipples, looking up at her intently. Kyoka bit her lip, adoring the way he lavished her chest.

Only then did he finally insert himself into Kyoka again. Thus began the last act to their insane group sex.

On and on they went, sun shooting across the sky. Izuku guessed it was sometime in the afternoon… they'd been going a full day? He didn't want to think about the state of their muscles afterward.

Momo had been sleeping for some time… hours, maybe? When Kyoka drew Izuku to her in the middle of his pressing her against the bed frame. It was a mating press, Kyoka's legs bent back as far as they could go.

"Babe… what do you think our kids would look like?"

"Huh?"

"I took to thinking about it the past few weeks… I'd always thought I'd fly from one partner to the next. But you drive a hard bargain mister. Think about it… Little Izukus."

Kiss.

"Little Kyokas…"

Kiss.

"So many running around, calling us papa and mama… We make the sexiest fucking couple ever, yeah? So breed me. Breed. Breed!"

Izuku's thrusts accelerated.

"Breed me, fucking breed! Breed, breed, breed, oh god, oh yes! Yes! YESSSSSS!"

Kyoka yelled, her ecstasy peaking. Izuku was sure to push and reach as far inside of her as they came. Blinding white light overtook both of them and their bodies shuddered at the sheer pleasure of their perfect orgasm. Then, at long last, they slumped against each other. It was clear they were utterly, entirely spent.

Getting off, Izuku pressed himself against the sheets. The entire room was, well, trashed. Different items littered the floor, from socks to broken drawers to a picture frame that had found its way into this spare room.

The room was hot from their body temperatures. So he made to get up… then instantly fell down.

"Ohhh… my legs…"

A pair of long, slender legs walked past him and opened the window.

"We finally done?" Momo asked. She was smiling gently at Izuku and Kyoka.

"Oh, I don't know if I've been more done in my entire life," Izuku said, gratefully accepting the water Momo offered him. He drained it all in three long gulps.

"So a twenty-four-hour threesome is finally what breaks the number one hero?"

"Oh shut up," Izuku said, chuckling along with Momo's laughter.

"Ughhhhh…"

Peeking up on the bed, they saw Kyoka burying her face into the pillow. She was so red they could see steam rising off her.

"Kyoka's back to Earth, huh?" Izuku asked. Kyoka flipped him off.

"Reverting to some bimbo slut was not in the fine print. Oh fuck, my muscles…" Kyoka groaned. She turned over onto her back, flopping helplessly and staring up at the ceiling. Izuku and Momo lay in bed on either side of her.

"I thought it was pretty sexy," Izuku mused.

"Shut up."

"I really enjoyed Thirst-Kyoka. Didn't know that level of arousal was possible." Momo remarked.

"Oh shut up Yaomomo!"

"You said something at the end there too. Something about kids—"

Kyoka pressed her hand against Izuku's mouth, blushing even redder. "That was… that was…! Ughhh, I'm not ready to talk about that yet. Can we just… you know…"

Izuku chuckled. "We'll file that one away for later. You hungry? We did it for a whole day."

Kyoka blinked. She looked out the window at the blue sky. "A whole ass day…? Fuck. Oh man… nah, if I ate anything I'd just puke. Why don't we… why don't we… Zzzzzzz…"

Kyoka slumped against the mattress mid sentence. She looked like she'd begun a century long sleep, exhaustion etched into every part of her face. Her large chest was steadily rising and falling.

"Of all of Mei's inventions, and there have been some crazy ones… this might take the cake."

"Oh yes," Momo agreed.

"Kyoka's right. Let's take another mulligan and just sleep for like… twelve hours. Or fifty years." Izuku groaned as he settled himself in comfortably.

"Sounds good." Their hands interlocked over Kyoka's stomach, and after some time their natural exhaustion did the trick and carried them off to slumberland.

In Mei's surveillance room, white light filled the dark room. Figures were huddled up on the couch in front of the giant screen.

"Fuck," Mina panted, hand in her pants. "Pay-per-view ain't got jack on this!"

"Izuku was so hoooooot!" Toru squealed, bouncing up and down.

Rumi and Kaina were staring intently at the screen.

"So he was still holding out on me!?"

"Body enhancement, huh…"

"All thanks to yours truly!" Mei smirked as she puffed out her chest.

"So I guess Kyoka's finally done," Rumi said. "How are Ochako and Itsuka doing?"

"Oh yeah, flip it to the lesbian channel," Mina requested.

CLICK!

The feed flipped over to the figures of Ochako and Kendo, lying asleep in a room similarly ravaged.

"What's the story here?" Toru chirped.

"Well we all know how it started," Kaina said, uncharacteristically blushing.

"Let's rewind it to when it started… I need to see that power move Itsuka did again."

Mina rewound the footage, swapping it over to the kitchen the previous day. And there Ochako and Itsuka's second infernal exchange of passion began…

Harem List:

Ochako Uraraka

Momo Yaoyorozu

Itsuka Kendo

Kyoka Jiro

Rumi Usagiyama

Mina Ashido

Toru Hagakure

Mei Hatsume

Kaina Tsutsumi

Big Boob Lovers List:

Cultured People (AKA everybody in the poly)

Hello everybody. Latest update. Hope the weather gets warmer soon. We move onto OchaKendo round 2, then a dedicated Izuocha chapter right after. And THEN… you'll have to wait and see.

I continue to be very excited to write all of these extremely horny scenarios. Izuku and Ochako's harem continues to grow and develop in numerous ways, with each member adding their own personal touch to make things more fun.

See y'all next time! Bye.