Remus shook his head. "It’s a rule. I go out, I lock the door. James’ always left his unlocked, open invitation is what he always called it, none of us ever locked our doors. Open invitation for you-know-who as well, I suppose." He winced at his own joke. Remus turned the door handle, muttering to himself. "Sorry, that wasn’t funny. Anyway, the door stays locked. Sirius won’t allow it anymore."