cw: bkdk , oral fixation , idk i'm just kinda writing lmfao

---

izuku has an oral fixation.

as soon as katsuki noticed, he couldn't unnotice it but the amount of times he'd walk into the kitchen and find him with a pen in his mouth, or walk into the common area and find him

watching the tv with a blanked out expression and a side of a finger stuck firmly to his lips.

what really confirmed it was when everyone was hanging out in the common room and someone had picked up popsicles. the moron just kept let it slide and slide down his throat with

glazed over eyes. katsuki watched as it went deeper and deeper, until it finally hit the back of his throat and izuku woke up. he pulled the popsicle from his mouth, and zoned back in, and apparently no one saw or chose to comment.

it was driving katsuki mad.

but it was also making him curious. does izuku want it to happen? or does he just blank every time something goes near his mouth. and the most important question to katsuki:

how would he react if someone else took part?

he was itching to find out the answer to that one.

so, the next time he walked into the common room and izuku was the only person there, with his eyes glazed over and the tip of his forefinger running across his teeth, katsuki decided he'd find out.

he walked behind the couch so as not to tip the nerd off before slowly leaning

over the back. izuku still hadn't even noticed, he was really out of it. before katsuki could back out, he gently reached out and knocked the hand out of izuku's mouth. instantly, he snapped out of his trance, looking over at katsuki.

"oh, hey ka-"

immediately, katsuki interrupted him by teasing two fingers across his lower lip before slowly pushing them in. izuku looked startled for a moment, staring up at katsuki with wide eyes. katsuki looked back, calculating, and started slowly dragging his fingers +

along back and forth, petting izuku's tongue. almost instantly, his eyes went blank and katsuki felt the slight pull of izuku sucking. he did that for another moment before pulling out slightly. as he did, izuku let out a small whimper.

smirking, katsuki pushed another finger along with the first two.

they stayed like that for a couple moments, but to katsuki it stretched on forever. eventually, he pulled his hand back and smeared saliva along izuku's bottom lip.

"good boy," the words slipped from his mouth unwillingly, and katsuki took a sharp inhale before noticing the deep sigh izuku let out. the drying spit on his fingers caused katsuki to straighten up and leave, taking the stairs up to the bathroom on his floor to wash his hands.

"huh," the blond said aloud as he mentally replayed the moment.

"huh."

((lemme know if i should finish this ! i'm kinda on the fence about it but if people are interested ))