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It started out innocently. Growing up, Katsuki watched how happy Izuku would get when Inko made her her favorite foods. She was usually a little reluctant to go home after their playdates were over, but having Inko tell her that there was hot katsudon waiting at home dissolved any pushback instantly.
“Oh, thank you, mama,” she would say so sweetly, nearly running out the door.
Katsuki took this as a personal slight. How could the little nerd choose pork cutlet over him? But Katsuki, the competitor that he’s always been, quickly decided that he could use her love of food to his advantage.
It started small, breaking all of his snacks in half to share with her. He would always offer and she would never refuse. Before long it became splitting lunches, Katsuki would take half of the food from his lunch and plop it into Izuku’s bento box when she’d finished devouring her own meal.
“But won’t you be hungry, Kacchan,” she would worry every day.
“Of course not. Eat it, nerd,” Katsuki would reassure almost fondly.
Izuku would thank him and devour the extra portion with little hesitation. Mitsuki eventually started doubling Katsuki’s food after a week of him coming home absolutely ravenous and grumpy.
The sharing continued throughout their schooling, but once Izuku and Katsuki started dating, just sharing his food wasn’t enough for Katsuki. After they got together, Katsuki started feeding Izuku himself. They would go out to eat, Katsuki would let Izuku order everything she wanted for both of them, and then Katsuki would feed himself one bite of food and then feed her two bites.
“Kacchan, please eat some more! I don’t want to take all of it,” she would whine.
“I’m eating. Just enjoy your food, Izuku,” he would smile.
And when they’d finally gotten engaged and moved in together, Katsuki started to cook every meal every day for the both of them. All of Izuku’s favorite foods, anything she wanted to try; even if he had a sixteen hour patrol, he would make sure all of her meals were portioned out and ready to go for her so she wouldn’t be hungry for even a second.
Katsuki was incredibly attentive about making sure that his fiancé stayed fueled for the day, but it wasn’t an entirely selfless endeavor. Katsuki loved watching Izuku eat, especially when she ate more than him. Seeing her pack away all that food, especially when she had One For All, reminded him how powerful she was. She needed all of that fuel to keep kicking ass on the battlefield. He was giving her the energy to be the world’s greatest hero.
And now that she was a full-time teacher, with the same appetite she had had as a hero, she was starting to put on some weight. Everyone had noticed. Her thighs had gotten thicker, her hips wider, her butt bigger, her stomach and face rounder. She was getting softer, shifting from a stout muscular frame to a plump, full figure.
No one had anything negative to say about the change, with the sole exception of a sleazy tabloid that ran a story on “The World’s Most Gluttonous Hero”. (The article was promptly pulled after their office was nearly burned down following a visit from one explosive hero.) On the contrary, all of Izuku’s friends were shocked by how much the extra weight really suited her. They had met her as a frail, bony kid that had stocked up into a muscular young woman, but now… she looked like a goddess. Her chest had filled out, the weight on her hips had given the illusion of a shrunken waist, her arms looked so soft and perfect to be held in.
The change did come with a few inconveniences though. Unfortunately for Izuku, all of her old clothing was now way too tight. Buying a whole new wardrobe was such a hassle, Izuku kept putting it off and just bought the bare necessities to get by with. But when she forgot to do laundry, which she did quite often, she would still wear her old clothes.
Katsuki’s mouth would water at the way her chest looked like it was going to rip the ill-fitting shirts in half. Her shorts that used to be perfectly modest now showed the bottom of her ass cheeks. And God forbid she forget to do laundry before the school week started. She would have to wear one of her old button ups, which refused to button over her chest and let her tits spill out of the opening for everyone to see. She would have to wear a sweater over the top of it so that only the collar was showing, but just knowing how she was spilling out of the shirt underneath of it got Katsuki riled up.
The only downside to all of this is that Izuku’s not gaining any more. Katsuki knows her mother, he knows Izuku has the genetic potential to get bigger, but it seems like she might be at her upper limit right now. She’s plump and soft and absolutely stunning, but Katsuki almost feels like he’s failing because she hasn’t gotten up to Inko’s size. Izuku eats endlessly, but she’s a busy body and she’s always going to burn a good amount of the calories he’s putting in her. But that’s okay, he’ll just have to try harder.
“Just one more bite, Izuku, please,” Katsuki whispers across their dining table, leaning forward with another large spoon full of the hot meal he’d prepared.
“Kacchan, I’m so full,” Izuku whines and Katsuki can feel his dick twitch.
“Please, I made it just for you.” He pouts as he moves the spoon closer to her mouth.
“Alright,” she whines again before opening her mouth and allowing herself to be fed.
“Good girl,” Katsuki praises softly, picking the dishes up off the table to put them in the sink. “I got you one more thing.” Katsuki makes his way to the freezers and pulls out a plate of a dozen mochi.
“But I didn’t save any room for dessert,” Izuku cries.
“You’ve always got room for dessert, Izuku.” Katsuki sets the plate down in front of her and puts a large hand on her belly. “Can I sit with you?”
“Of course, Kacchan!” Izuku stands to let Katsuki take her seat and then plops down heavily onto his lap. The weight of her on top of him is getting his dick even more interested. He tries not to make it obvious, but there’s no way Izuku can’t feel his arousal. “Kacchan, let’s-”
Before Izuku can finish her suggestion, Katsuki has the first mochi pressed to her lips. “Please.” The sound almost comes out broken, he really needs this.
Izuku opens her mouth and allows the mochi to push past her lips until she bites down. She chews while looking down at Katsuki, she can’t help but smile at how sweet he’s being. So docile when he wants something from her.
“Thank you, Kacchan, it’s very yummy.”
“Fuck,” Katsuki moans and tries not to buck his hips. “I-I love you.”
“I love you, too,” Izuku laughs and bends down to kiss him once on the lips. Katsuki can taste the sweetness lingering from the mochi. He puts the second half to her lips and she complies by finishing the piece in one bite. He lets his hand linger near her mouth as she finishes chewing, once she swallows she gently sucks and licks the rice flour off of the tips of his fingers.
“Shit, Izuku-” He can’t hide the way he’s grinding up into her now and he doesn’t try. He wraps his arms around her waist, grabbing her stomach and continuing to push up into her. “I need-”
“I know what you need, Kacchan,” she laughs and stands up. Katsuki is saddened by the loss but holds her hand as she leads them to their bedroom. She lets him through the door before shutting it behind him and leaning back on the door. “On your knees.”
Katsuki crumples to the ground and grabs the waistband of her skirt. “ Can I take this off? Want to see you.”
“Nope,” she giggles and lifts her skirt. She isn’t wearing any underwear. Katsuki can see the soft green curls framing her pussy. Her cunt is cute and chubby just like the rest of her, already damp with arousal and hot to the touch. He uses his fingers to gently spread her open.
“Can I,” Katsuki begs, looking up at her.
She nods with another chuckle and then there’s a hot tongue on her clit. “Kacchan!”
He hums in response, but gives no other acknowledgement. He’s busy working broad, slow licks over that sensitive spot. His hands squeeze the soft meat of her thighs to keep her legs open. He’s been unintentionally choked out enough times to know what precautions to take by now.
Her hands find the back of his head where she grips the short hairs at the nape of his neck. She uses the handful of hair to guide his movements, set the pace. She loves it slow at first, wants to take her time getting worked up for him. It drives her a little crazy, but it builds the best orgasm for her. Then all too soon that hot mouth is gone.
“Please sit on my face,” he lets out between heaving breaths. The bottom of his face is glistening with spit and slick.
An eager nod leaves her as she shucks her skirt and they both scramble to the bed. Katsuki lays out, still completely clothed and ready to be used. Izuku kneels above him, quickly straddling his head and lowering herself to Katsuki’s waiting mouth.
“Fuck,” she exclaims as he works his tongue over her clit at a ravenous pace. “Kacchan, that’s so good!”
Another hum of approval from below her as Katsuki keeps his tongue moving, her hips moving to meet each lap. Izuku vaguely remembers, when she had first started putting on weight, how she was suddenly less brazen when they were intimate, dawning a timidness that was entirely unseen before. She had known Katsuki all her life and had known he was the only one for her, so she had never before felt unsure in moments of intimacy. Katsuki had noticed her hesitance and had insisted on pampering her for weeks. Weeks of nothing but worshiping every inch of her body, only focusing on making her feel good, not worrying about getting himself off, until she was back to her usual confidence. For those weeks, he begged Izuku to sit on his face for hours while he ate her out leisurely, enjoying her weight above him, encouraging her to press down harder.
Now Izuku didn’t hesitate to let her weight fall on his shoulders or his gorgeous face. He is strong and capable and she knows how much he loves being under her. Katsuki’s hands glide from her thighs to her ass, grabbing large handfuls of each cheek before pulling her down to meet his rhythm. Izuku knows what he’s asking for.
“Want me to fuck your face, Kacchan,” she giggles breathily. She can feel his head nod, never breaking contact with her pussy. With his confirmation, Izuku begins rutting her hips down in a steady pattern as Katsuki shifts from licking to sucking her now swollen clit. “Holy shit, your mouth feels so good- You’re gonna make me cum, fuck!”
Katsuki knows to keep the pace and pressure steady at her admission. Continuing to pull her down and suck her nice and hard in tandem while she chants praises repeatedly. “I’m cumming! I’m gonna cum in your mouth, Kacchan- Yes!”
Katsuki feels her walls begin to shudder as her clit pulses repeatedly in the wet heat of his mouth. He lightens the pressure on her and allows her to slow the pace of her thrusts at her own leisure as she rides out her orgasm, body trembling with waves of pleasure.
Izuku lifts her hips just out of reach of Katsuki’s advances but remains hovering over him while she unbuttons his pants and starts to pull them down his thighs along with his underwear. He takes the hint and helps to finish removing them without moving from underneath her. He’s painfully hard and he needs something to take the edge off. Katsuki begins to reach for his cock before his hand is swatted away with a tsk.
Izuku leans forward and swallows down his dick in one swift movement causing Katsuki to jolt in surprise. His fists ball into the sheets as he resists the urge to make any movements without her explicit permission. Izuku gives her head five or so good bobs before she’s pulling off with a loud pop.
“You don’t need that, Kacchan,” Izuku declares as she grabs his thighs and pulls them back to his chest. Bending him in half, she takes the opportunity to spit on his exposed hole. “You need this, right?” She uses her finger to rub the spit into his tight hole before pressing one finger in down to the knuckle.
“Yes,” Katsuki cries out. “I need it, Izuku. Please!”
Izuku removes her finger and laves her tongue over the tight furl of muscle. They groan in unison as Izuku teases his asshole with her sinful tongue. “Please, what?”
“Please fuck me, Izuku,” he sounds desperate. “Please, baby.”
“Let me finish stretching you, okay?”
“No! No, I can take it. Please let me take it now. I need you to fuck me now, please, baby. I’m ready, I promise!”
“Yeah? Are you sure,” Izuku pries, shoving two fingers into his ass.
“Yes! Yes!”
“Okay, baby, go get the strap.” With that, Izuku releases his thighs and allows him to retrieve the strap-on stashed in their nightstand. They used to hide it in the closet in the slim chance someone went snooping, but at this point it’s used nearly every time they fuck and it’s simply not worth the hassel of concealing.
Katsuki turns back around wielding the large silicone dick. Custom colored to perfectly match Izuku’s skin, a modest six inches, but incredibly thick - absolutely perfect for abusing her fiancé’s prostate. Katsuki untangles the straps and holds the harness open for Izuku to step into.
“Thank you, baby,” Izuku coos as she allows Katsuki to pull the harness up her supple thighs. She holds the contraption in place as Katsuki tightens the straps to hug her tightly. “On your back.”
Katsuki complies hastily, pushing himself back to the center of the bed and sprawling out, spreading his thighs to welcome her. Izuku crawls between his open thighs and gives his cock two light tugs watching his eyes roll back. He doesn’t get external stimulation very often, so he is particularly sensitive. Izuku releases and Katsuki takes the opportunity to grab his thighs and spread his hole for her to see.
“Please,” he breathes out. Izuku doesn’t bother responding, just lines her strap up to the tight ring of muscle and starts pushing. Katsuki lets out a strangled groan as he’s forced open. There are already tears in his eyes, he didn’t prep as much as he should’ve, but he always enjoys being roughed up a little in bed.
Izuku sets a brutal pace from the start. Katsuki likes being cared for on occasion, but more than anything he loves taking whatever Izuku will give him. Letting her decide what he needs, showing her he’s strong enough to take anything for her. It’s a point of pride for him to keep up with her demands, and Izuku has many. She enjoys being able to be hard on Katsuki. Never mean, but stern, strict, rigorous in her testing. They’re competing for the number one hero spot and this is no different, friendly competition.
But in the bedroom, Izuku always wins and it’s never close. Katsuki gives himself willingly and lets her break him down over and over again. Overstimulation, punishments, edging, chastity, whatever she wants, without question. Katsuki hasn’t denied a single sexual request yet, and he takes pride in that.
Katsuki looks absolutely debauched, mouth open, panting in time with Izuku’s relentless pace. His eyebrows pinch up, almost in disbelief of the way she’s turning him out. She licks into his open mouth and then spits, he swallows without thought.
“You’re gonna break me,” he whimpers, words jolting from him with each thrust.
“You’d like that,” Izuku laughs in his face.
“Yes! Yes, please break me,” he admits. “Please, mommy.” Katsuki slaps a hand over his mouth, clearly shocked at his own words.
Izuku never slows her pace, simply removes his hand to lace their fingers together. “Aw, baby! You want mommy to break you?”
Katsuki nods so hard he almost headbutts her, the eagerness tickles Izuku. She uses her free hand to wipe a tear from his cheek and quickens her pace. Katsuki’s full-on crying now, he’s so overwhelmed and embarrassed by his outburst.
“It’s okay, baby. Mommy’s got you,” Izuku whispers sweetly. She can tell he’s close, he’s nearly holding his breath as his ass grips her dick even tighter. “You wanna cum for mommy?”
No words come out when he opens his mouth to respond, just garbled noises that sound like confirmation to Izuku. She keeps up the brutal pace, always angling her hips to make sure she’s hitting her target.
Something that sounds like “mommy” escapes Katsuki’s lips as he does his best to push back and meet her thrusts.
“Good boy, just like that, Kacchan. Be good and cum for mommy.”
And suddenly Katsuki’s hips are jerking while he spills his load onto his stomach with a pained sob.
“Always so good for mommy. Thank you, baby,” Izuku whispers before planting a chaste kiss to his panting mouth.
“Love you, mommy. Thank you,” Katsuki heaves out between gulping breaths.
“Anything for my good boy,” she smiles. “Open.”
Izuku scoops the cum off of his abs as Katsuki’s mouth drops open at the command. Her fingers push his tongue down before pushing back into his throat. He doesn’t even gag anymore, she’s trained him enough on her strap that he could deepthroat just about anything for her. He sucks the spend off of her fingers, making sure to lick between each digit, leaving no trace of his release on her. She removes her fingers and wipes his spit on the side of his face. He stares up at her in reverence, taking one last gulp before sticking out his tongue to show he’d cleaned his mess.
They clean up quietly. It’s always peaceful in the aftermath of such heat. They shower together, Izuku makes sure to take her time washing Katsuki and covering him in sweet kisses. When they’re done they don’t get dressed, just replace the sheets together before climbing in and cuddling up to each other.
Katsuki can feel Izuku’s breath on his cheek when she whispers, “Do you want to talk about it?”
He shakes his head and lets the silence draw on. Izuku’s hand finds his hair, brushing his bangs back to really look at him. She doesn’t push, she doesn’t need to; he’ll talk when he’s ready.
“There’s not much to say,” he finally states. “I love you, thank you for doing that for me.”
“I love you, too. And I didn’t just do it for you, I enjoyed it.” Katsuki admires the way that her eyes crinkle with her smile. “Thank you for trusting me, and for letting me be your mommy.”