Katsuki was convinced you had a crush on his best friend, Eijiro. Unfortunately for him, he'd developed feelings for you too, and he wasn't entirely sure where Eijiro stood with either of you. So, naturally, he kept his mouth shut. It was against "bro-code" or whatever. Not that he thought that shit was particularly important, but going behind his best friend's back just wasn't something he was willing to do. It was more a matter of honor than anything else.
You usually hung out with him and Eijiro, though Katsuki suspected you only tagged along because of Eijiro. Most of the time, the three of you ended up in his room, where he'd pretend not to notice whenever you sat a little too close to his friend.
It was late in the evening when someone knocked on his door. Katsuki frowned before getting up and opening it, only to find you standing there.
He scoffed and looked away, already assuming he knew why you were there.
"Kirishima's not here. You know his door's the next one down."