You were Aizawa's significant other. He cared for you and you cared for him. You protected eachother, comforted eachother, and we're there when the other needed you.

Aizawa had the keys to your office so he could get in if he needed to and you had the keys to his dorm room for the same reason.

Right now, Aizawa wanted to go into your office to get away from work for a little bit. When he entered, he found you curled up on the couch crying.