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Katsuki tried to pay attention to the book he held above his face, but he was distracted by his boyfriend’s hair tickling his neck and his restless fingers fiddling with the blond’s shirt. Katsuki could tell that Izuku had something on his mind. Deku had shyly knocked on his door, saying he just wanted to be around him and had been mostly silent since then.
Izuku nuzzled into Katsuki’s neck, and Katsuki felt his patience break.
He shut his book and lightly bopped Izuku’s head with it. “Oi, spit it out already,” he ordered.
Izuku startled and grabbed his head. “Owww,” he whined, even though it barely hurt him. He put on a pouty face and looked up at Kacchan. “Meanie. How do you even know I have to say anything?”
Katsuki rolled his eyes and grabbed his boyfriend’s chubby face. “It’s a rarity that I don’t hear your yapping nonstop. You only stop when you’re worried about something you want to say.”
Izuku marvelled at Katsuki. He was so perceptive. Izuku was honored that his Kacchan paid as much attention to him as Izuku did Kacchan. But, he blushed at being read so openly. “Ugh, it’s really stupid and silly and embarrassing,” he rambled, hiding his face against Katsuki again.
Katsuki leaned over Izuku, feeling excitement rise in him. “Oh, is it, now? What could possibly be more embarrassing than your usual self?” he teased.
Izuku tried to duck away from the blond’s intense staring. “But what if…you don’t want to hear it,” he mumbled.
Katsuki sighed and stroked Izuku’s curls. “Stupid Deku, just spit it out. What, you want to fuck or something?” He meant it as a joke to get Izuku to stop panicking.
But, Izuku just whimpered. “I mean, sort of, but in a specific way?” he muttered. He looked like a tomato under his hands.
“God, you are such a dork,” Katsuki laughed with relief.
Izuku swatted at him. “Don’t laugh at me!” he whined.
“I thought you had some terrible dark secret to tell me, but no, you just have some kinky fantasy or some shit?” Katsuki chuckled, ruffling Izuku’s hair. “What’s so dirty that you can’t spit out, baby?”
Izuku got bashful again at the pet name. “Arghh, I just don’t know how to ask what I want,” he stammered. “I don’t want it if you don’t want it…”
Katsuki frowned. Izuku got so worked up over sex. Katsuki wasn’t totally oblivious as to why though. With Izuku being trans and having terrible self-esteem in general, he wasn’t the most comfortable with intimacy when their relationship first started to heat up (which admittedly happened very quickly). Katsuki had to do a lot of convincing that he genuinely wanted Izuku before they first fucked. But, since then, Izuku seemed pretty non-hesitating to get his pussy filled by Katsuki. So, Katsuki was confused at this sudden anxiety.
“Baby, this is a two-way street. We tell each other what we want and don’t want,” Katsuki said, grabbing Izuku’s hands from his face.
Izuku sighed and nodded. “I know, Kacchan is right—”
“Always am.”
Izuku giggled. “Mhm, Kacchan’s always right,” he agreed softly and leaned in for a kiss.
Katsuki gladly captured Izuku’s soft lips with his for a sweet and chaste kiss.
Izuku felt lighter and already a bit wet at Kacchan’s tender affection. He ducked his head down and took a deep breath. “Okay, ummm, could we try…buttstuff?” He peeked one eye open at Katsuki.
Katsuki’s dick immediately twitched at his boyfriend shyly asking him to fuck his ass. He wolf-grinned and got closer to Izuku. “Babe, you thought I wouldn’t want to fuck that sweet ass of yours?”
Izuku’s flushed red and tried backing away, but Katsuki circled his arms around his slender waist, holding Izuku in place. “I don’t knowwww. Maybe you’d think it’s gross or think I'm weird for wanting it,” he floundered.
Katsuki nosed Izuku’s neck and started nibbling into the soft skin. “I always figured you’d be some disgusting freak in bed, but this is pretty tame, Deku,” he teased.
Izuku humphed and grabbed Katsuki’s biceps to steady himself. “You’re the kinky one…always making fun of me and biting me,” retorted with a shaky voice.
Katsuki hummed into his skin. “Maybe, but you’re the one with the soaked panties.”
Izuku’s heart flipped, and he let out a small whimper.
“You want me to touch you, Izuku?” Katsuki growled in his ears.
The boy nodded.
Katsuki grabbed his green curls harshly. “Not good enough, baby. Tell me what you want,” he demanded.
Izuku visibly swallowed. “Kacchan, please…Play with my butt,” he whispered and flushed red.
Fuck, Katsuki thought with an out loud groan. Izuku’s damn whiny voice and cute face asking for his Kacchan to “play” with his ass… A scene right out of Katsuki’s wet dreams.
Katsuki grabbed Izuku’s plump waist and pushed him down onto the bed. He forcefully pried Izuku’s lips open with his own and shoved his tongue into his mouth. Izuku let out muffled cries of shock and pleasure as Katsuki near-suffocated him. Meanwhile, Katsuki used one hand to un-do the knotted strings of Izuku’s pants and start prying them down.
Izuku felt what Katsuki was attempting and lifted his butt to help him. He pushed Katsuki’s mouth away and panted for air. “Want your clothes off, too, Kacchan,” he pleaded.
Katsuki grumbled and hurriedly freed himself from his shirt and shorts as Izuku shakily finished removing his pants.
“Taking too damn long,” Katsuki huffed and yanked Izuku’s shirt off for him.
Izuku shivered under Katsuki’s intense gaze at his bare skin. Only his panties remained on him. Izuku glanced down Katsuki’s body and saw his bare cock out and chubbing up. He flushed and quickly looked back up at Kacchan’s face, which was now smirking at him. Embarrassed at being caught peeping, Izuku turned his head to the side and whined.
Katsuki felt like there was a beast inside him that wanted to lunge out at Izuku’s sign of submission. He instead held back and only lightly nipped at Izuku’s skin: under his ear, his neck, the small raise of his breast, his plush tummy.
He tugged at Izuku’s panties. “I’m gonna take these off, okay?”
“Mhm,” Izuku gave his approval. He doubted he could get a word out.
Katsuki pulled the green silky fabric down, raising Izuku’s legs for him to pull the underwear completely off.
Izuku turned his knees slightly inward to hide his private parts.
Katsuki slid his rough hands up Izuku’s smooth thighs and pulled them apart, making Izuku squeak. Katsuki drooled at the sight of Izuku’s pink pussy, already slick at the lips. He dragged a finger through the slick and teased Izuku’s twitching clit.
“WAH-chan!” Izuku spasmed at the sudden touch.
“Sp jumpy, baby,” Katsuki hummed. He kept idly rubbing Izuku’s hard clit, relishing in the boy’s twitching.
“Sssenstiveee,” Izuku whined and tried to buck away from Katsuki’s hand.
“Let’s move on to your ass, then,” Katsuki told as he moved his hands away to grab lube from his nightstand. Izuku whimpered and made grabby hands at him. “I’m right here, baby. Need lube for this.”
He poured some on his pointer and middle fingers and rubbed it around to make sure they were wet. He used his other hand to raise Izuku’s legs up so that he could see his asshole.
“Gonna finger you so you get used to something up your ass, alright?”
Izuku nodded and grabbed Katsuki’s hand that was on his waist.
Katsuki placed his wet fingers to Izuku’s hole, which was already slightly wet from pussy slick dripping down. Izuku flinched but relaxed back. Katsuki gently pressed his fingers inside the hole and ever so slightly wiggled himself inside.
“Ah, nnn,” Izuku whimpered at the new feeling.
Katsuki marveled at how fucking tight this hole was. But it wasn’t near as wet as Izuku’s cunt, so he drizzled more lube down his fingers so it would seep into the hole.
“That felt weeeiirrd,” Izuku whined.
Katsuki chuckled. “Sorry baby. It’ll warm up soon,” he soothed.
Katsuki wiggled his fingers in deeper, and they slid easier this time. He quickly had his fingers seated fully inside. He patted Izuku’s hip. “Untense your muscles.”
Izuku tried to steady his breath and let himself sink deeper into Kacchan’s bed. He closed his eyes and took in Kacchan’s scent all around him. Kacchan was inside him. In his butt. Mmm. He unknowingly started rocking his hips down to feel Katsuki’s fingers better.
“I guess you’re ready then,” Katsuki teased. He gripped Izuku’s waist to keep him still so that he could control the pace.
Katsuki then began to fuck his fingers back and forth in Izuku’s hole, getting Izuku used to the movement inside him.
“Ahhh ahhh, Kacchan, feel really full” Izuku squirmed. What first felt weird and uncomfortable was building into a warm and pleasurable sensation.
When Katsuki saw Izuku’s pussy start slicking again, he knew Izuku was getting into it. He began to drag his fingertips upwards and rub into the back of Izuku’s g-spot.
“GAH! NNN! My butt feels good,” Izuku babbled out.
“Yeah, baby? You like having your ass played with?” Katsuki encouraged Izuku’s blissed-out babbling while getting faster with his fingering.
“Oh! Oh! MMM! Izuku like Kacchan in his butt! Feels so good. Full and warm,” Izuku started giggling, and his head lolled to the side. “Can feel it in my cunnie. AHhhahhh.”
Katsuki rammed his fingers harder into Izuku’s ass.
“GAH!” Izuku gasped and twisted. “I feel it! Gonna…” He squeezed his eyes shut. “AH AH AH!” His stomach tensed up, and Katsuki felt a vice around his fingers. “COMING! HHHHHuuuhhhh, Kacchaaaaan,” Izuku screamed and whined.
His ass rhythmically squeezed around Katsuki’s fingers. Katsuki watched as Izuku’s pussy dribbling slick out the pulsating hole. It soaked his hand and made Izuku’s ass wetter. Katsuki slowed down his rubbing and eased his fingers out. His other hand slid down to Izuku’s gushing pussy to rub and soothe it down from orgasm.
Izuku shivered underneath him.
“You liked it, baby?” Katsuki asked.
“Mhm,” Izuku giggled.
“Good,” Katsuki hummed and leaned down to kiss Izuku softly. Izuku pawed at his chest and nuzzled into his face. God, he was adorable when he was fucked-out. Katsuki’s hips instinctively humped down into Izuku’s soft body to relieve his aching cock.
Izuku looked up at him with glossy eyes. “Wan’ more,” he mumbled.
“What do you want, baby?” Katsuki demanded.
“Wan’ Kacchan’s cock in my butt,” Izuku giggled. He shakily wiggled himself around and laid on his tummy, pressing his ass upward. “Please, use my butt, Kacchan.”
“Fuck,” Katsuki gruffed. He leaned back to marvel at Izuku’s gorgeous ass. Plump and freckled. He lightly spanked the right cheek to watch it jiggle and blush pink.
“MMM!” Izuku squealed.
Katsuki did it again. And again and again. He spanked Izuku’s cheeks until they were bright red, and Izuku only whimpered and raised his butt even higher. Katsuki grabbed Izuku’s ass with both hands and squeezed the ample fat; he pulled and pushed the mounds around, like kneading dough.
“Kachaaaan,” Izuku whined with need. “Pleeeasssee.”
Katsuki gave him another spank. “I thought you wanted me to play with your ass,” he teased.
“Inside!” Izuku poutily demanded. “Wan’ Kacchan insiiiideeee.” He sounded like he was crying now.
“Shhhh, baby, your Kacchan’s gonna fuck you now,” Katsuki reassured. He grabbed the lube again and poured some on his dick, hissing at the cold. He stroked his cock to get it wet. “Goddamn,” he hissed at the pleasure and pulled his hand away.
Finally, he was ready to fuck Izuku’s ass. He spread Izuku’s cheeks apart and looked at the still-wet hole, winking in expectation of being filled. Katsuki directed his cock to the hole and pressed the tip inside.
“Fuuuuuuuck.”
“Kachaaaaan.”
Katsuki carefully pushed his dick further inside, keeping tabs on Izuku’s reactions.
“Yes, yes, please, fill me up!” Izuku mumbled into the pillows. “Kacchan…so big. NNNN!”
Katsuki felt like he was splitting Izuku open with how tightly his dick was being squeezed. He gritted his teeth as he sunk all the way in. Resting his head on top of Izuku, he kissed Izuku’s sweaty skin as he steadied his breath. “Good boy taking me all in. Ready for me to move?”
Izuku let out a loud, high-pitch keen at the praise. “Please use me please use me please please please!” he babbled.
Katsuki’s hips bucked forward, deciding to fuck Izuku for him. “Shit, goddamn it,” Katsuki swore. “Baby, your ass is so tight and hot.” He couldn’t help but set a desperate speed, ramming in and out of Izuku’s hole.
Izuku melted completely onto the bed, causing Katsuki to basically fall on top of his body and keep bucking his hips frantically.
Crushed between Katsuki’s big body and the bed, Izuku felt light-headed. His open mouth drooled on the pillows. He was getting addicted to the feeling of being completely used by Kacchan. “Deep…shoo deeEEep,” he babbled. “Feel Kacchan–ah ah–in my guts. Hahhhhh.”
Katsuki plowed Izuku harder, feeling and hearing lube and his precum splash out of Izuku’s hole with each thrust. “Such a fucking buttslut!” he growled. “You love having your Kacchan use your tight asshole, ignoring your slutty pussy.”
“Ohhhhhh!” Izuku’s breath hitched.
“Even like being called out. You goddamn. Butt. Slut,” Katsuki spat out. He spanked Izuku’s ass again.
“AH!” Izuku cried out.
His butthole clenched around Katsuki’s cock, and Katsuki heard a splash land on the bed.
“You fucking squirted?!” Katsuki laughed deliriously. “Your untouched slutty pussy squirted by having your ass fucked? Fuck, you were made to be used, whore.” He gripped Izuku’s waist harder and used him like a damn fleshlight to furiously jack off his dick.
“YEsss, yessss,” Izuku whined, gasping for breath.
“Gonna come so hard for you, baby. Where do you want it?” Katsuki gruffed out.
“INSIDE! Inside, please. Please cum inside. Fill my butt with your cum, Kacchan!” Izuku eagerly cried out, panicking at the thought of Kacchan pulling out.
“Gonna pump your ass full, baby, don’t worry,” Katsuki growled. He slammed his cock in Izuku’s ass hard three more times, and his balls unleashed hot cum, flooding Izuku’s hole. “Fuuuuuuck.”
Izuku preened at the new feeling of being filled. He relaxed and felt himself floating into sleep.
Katsuki gave a few more thrusts inside Izuku to ride out his orgasm, and he watched as his cum frothed around Izuku’s butthole. The boy was filled to the brim. Once Katsuki’s dick felt a bit raw and overstimulated, he finally pulled out.
Cum oozed out of Izuku’s hole and down his pussy. Katsuki, mesmerized, played with the cum and pressed it back inside Izuku’s butt.
“Mmmhmmnnnn,” Izuku whined in complaint.
Katsuki knew Izuku was about to pass out and that he’d have to stop playing with his butt for now. He tore his fingers away from Izuku’s ass. Giving into temptation, Katsuki gave a quick kiss to the soaked puckered hole.
“EEP!” Izuku squeaked.
Katsuki grinned at the reaction. He turned Izuku back around to face him. His boyfriend was limp in his arms and could barely keep his eyes open.
“You came so fast, baby. You must have really liked it,” Katsuki teased.
Izuku nodded and nuzzled into Katsuki. “Felt nice,” he muttered simply. “Kacchan liked it?”
Katsuki snorted and pulled Izuku closer. “Hell yeah, I did. Gonna use you more like that.”
Izuku grinned dopily against Katsuki’s skin. “Sleep now, kay?”
Katsuki rolled his eyes. They and the bed were a fucking mess, but yeah he was also feeling like a cuddle after that. “Okay, baby. Sleep now,” he cooed.
He swaddled Izuku in blankets and his arms. Katsuki just watched Izuku sleep, stroking his sweaty curls and soft face, and devising plans to buy huge butt plugs for Izuku to wear during school.