cw: brothers best friend trope, late teens-early twenties, mutual yearning, crushes, katsuki is down bad, sleepover, kissing, swearing, & not proofread
ⓘ Featuring brothers best friend Kats can't help but think about Kirishima's little sister.
katsuki knew he was done for the first time he came to Kiri's & found you opening the door to welcome him—it wasn't even supposed to be something meaningful, gaming & dinner, but he found you and just knew.
katsuki started coming over regularly. Everyone wants to study? Let's go to Kirishima's. Movie night? Kirishima's house has the best snacks. Sleepovers? Since you're there, Mina & Jirou can come; it's only logical to be at Kirishima's.
katsuki would bring extra snacks & offer them to you because he noticed you sneaking downstairs to raid the kitchen, is always quick to pass you a plate, or bowl, or just a brownie—before your brother gets the chance most of the time.
katsuki thinks he's slick about his crush, but it's painfully obvious to just about everyone but you.
katsuki started figuring out little ways to include you in the friend group, blissfully unaware that the moment he suggested bringing you, Kirishima was expecting to be told you were dating soon after.
katsuki who snuck into your room one night during one of the sleepovers, his friends were bickering over a video game, & he took the opportunity, finding you getting ready for bed, making a fool of himself, and accidentally started a domino effect.
You'd always end up seeking the other out.
katsuki ends up crashing in your room at every chance, claiming the atmosphere was "too loud." from the extras & started spending more time tucked in your room than out with his friends.
katsuki dozed off in your bed one night while you were showering & woke up to the feeling of your damp hair prickling against his chest, dazed & out of it at the sight of you cuddling up against him.
katsuki silently wrapped an arm around your shoulder, stroking your shoulder slowly & watched you get more comfortable against him, letting you live in it & take it as it were, you felt safe with him.
katsuki only woke up from the flash of Mina's phone at 3 am, where his friends were all crowded around your bed snapping photos of you using Kats as your personal teddy bear—glared at them, silencing them with a single eye twitch and hissed "If you wake her up, I swear to god—"
katsuki didn't move a muscle & stayed put after Kirishima finally dragged their friends out of your room with a quiet "we're talking about this in the morning." as he motioned between you both before leaving.
katsuki completely forgot he'd been annoyed the moment he felt your fingers lazily stroking his chest, & froze up when your lips softly pressed against his cheek.
katsuki knows he's completely smitten.