What's the reason?

Me and my " the one that got away" finally see each other after a year. We have great sex , we're kissing giving each other oral and everything. I'm a little hesitant because he has pushed me away before. He doesn't want to leave and I don't want him to leave but he says he was going to talk to me later and to tell him when I want him to come back. The whole time he's over here he constantly mentions " the next time he comes over". He leaves and I don't hear from him that whole day, I inboxed him the day afterwards and he replies but leaves me on read afterwards. I don't understand , we've been pursuing each other for a year it's obviously we was missing each other .. I just don't understand.