I would talk to him, take a chance and tell him what you've said here; what have you got to lose? I don't think you can "trick" him back or slip back in to his feelings while he's not looking :-) anything like that. I think a whole lot of honesty and communication is the only way to go. I don't think it's a good idea to assume things either; when you were saying you thought he might still care for you since he let you move back in, my thought was that he might feel sorry for you! Two different directions that only he can answer. Talk to him!