"Keep doing that again and ill have to teach you a lesson myself, Deku." Katsuki’s voice rings.

Late at night, Izuku huddled over his desk, back arched as he mindlessly graded papers. Ever since Katsuki and Midoriya had even moved in together, Bakugou had noticed early on what Izuku’s bad habits were, and he was determined to fix them, no matter the method.

That's when Midoriya feels the door click open behind him.