Izuku has been strangely clingy today. He refused to leave Katsuki's lap even though class was starting, for the first time in his life, he accepted pets from anyone and seemingly enjoyed it, meowing and chirping when they stop petting him, rubbing his cheeks against them. Katsuki was confused by it at first until he had to wrestle off a random person with a cat quirk as well off Izuku who presented himself to them on all fours.
"Holy shit you're in heat." Katsuki mutters, lifting Izuku off, the teen purrs and chirps, curling to his owner happily, rubbing their cheeks affectionately.
"Kacchan- Kacchan lets play!" Izuku murmurs, "oh wait no! Take me out on a walk out the park! Let me meet new friends Kacchan! I love making friends! Kacchaaan!"
"No way you'll just fuck someone while I'm not looking, let's get you home kitten."
"Noooo, let's not go home Kacchan- Hey Kacchan touch me!"
"Kacchaaan..." Izuku whimpers, "come on please? Don't you think I'm cute? My friends say that I'm cute, don't you wanna touch me?"
Katsuki responds by petting him, Izuku quickly presses up to the blond more, purring, his tail curled around him as well as he relinquished in his owner's touch, as much as Katsuki wants to keep doing this- he really really-probably really needs to get home, his cat dad instincts are tingling and he can smell more cats approaching, holding Izuku tight, he runs away from that place.
"Auntie! Deku's in heat!" Katsuki screams as he barges through the door, it was all so nice the first half of the trip, Izuku fell asleep leaning on him and then he promptly tried to pull Katsuki's dick out and then promptly ran away when Katsuki threw him off.
Katsuki had to run after him and then had to fight like 3 cat persons ( why are there so many people with cat quirks what the fuck- ) from defiling his cat. Stupid cats, he refuses to have his cat mated damnit.
"Oh my, thank you for bringing him home- did he get into any trouble...?" Inko attempts to take Izuku into her arms but the greenette only whined, hissing as he clung tighter to the blond.
"No! Not Kacchan, stay away!" Izuku hisses, Katsuki felt flattered, really, but he's been carrying Izuku for like an hour and his muscles are starting to strain, especially since the greenette moved so much.
"Why don't you sit on the couch first? I'll get you both something to eat and drink. I'm sure Izuku wants to spend more time with you." Izuku let's out a happy purr, nodding as he reached up to kiss Katsuki on his cheek before burrowing his face in his neck. Katsuki didn't blush. He didn't.
Inko giggles before she returns to the kitchen. Katsuki removed his shoes and Izuku's before he walked and sat down on the couch. Izuku quickly settles himself on his lap, hugging the blond and relinquishing in his warmth, Katsuki hesitantly hugged back, this is... nice.
Or would've been nice had he not felt the greenette slowly grinding down unto his dick with soft desperate chirps,
"D-Deku-" Katsuki hisses, gripping his hips to stop them from moving, it seems to send the wrong signals up Izuku's brain, letting out a soft whimper.
"K-Kacchan- please I need it.." He crooned desperately trying to grind back down, "don't tease...please."
"Mhm, you'll bruise my hips if you hold me down that tight..."
Katsuki released Izuku in a panic before realizing why he was doing this in the first place and did it again.