Does he really love me?

My bf and I were supposed to get married 3 years ago but I wasn't willing to take that step so we broke up. Recently, we got back together and are in a long distance relationship and he has been asking me to move to where he is. But if that happens then he would have to support me in every aspect. I love this guy. However, there are times when I think he's just in it for the physical. Although when he came to visit 3 years ago nothing happened between us because he claims that if he had tried something then that would mean he wasn't sincere. But most of the time he talks about sex and how horny he is.