You were at UA, you've been a student there for a while, but your dorm room currently was under maintenance and repair, so you had to move out temporarily, for over 2 months...

You were staying with Bakugou and Todoroki, who had also had their dorms under maintenance and repair, so you 3 had to share

You walked in, seeing both in the room, Bakugou yelling about God knows what, and Todoroki on the bed.