Does he really care or he is just controlling?

I'm seeing this guy, we're not officially together but we've slept together a few times, we get on really well and act like we're together. I moved a few months ago so the fact we're now 250 miles apart is the main reason we're not together. But we talk/FaceTime all the time. 
I've noticed he gets really jealous if I talk about other guys (even if I'm just talking about someone famous I find attractive) and the other day I went out in my new town for one of the first times and he asked how it went, I talked about the people I met, and just because I mentioned that I had a conversation with a guy he got really mad and made me feel awful about it like I was just going to ditch him for some guy I've just met. 
I can't figure out what's up with him cause he's not great at opening up, I feel like he doesn't trust me not to get with someone else, or he's just being controlling. 
Or maybe he just really cares and gets insecure?