When can i talk to him about personal things?

It's probably not weird for you to come out and say, "Are these rumors true?" He will hopefully just think you're curious, not a stalker. If you are too nervous about this though, then you have a few options. If he has a girlfriend now, you can ask about what he's going to do when he moves. Then move on to ask about other girlfriends. If he doesn't have one then when chatting you could say something about your love life (just something simple like, "this guy keeps texting me but I don't really know how to tell him I don't like him") then ask him, "what about you? I know you've had girlfriends in the past. What would you do?" then ask if he doesn't mind you asking about these rumors. Good luck!