I have been talking to a US Marine for the past 6 months and last year before he graduated high school we hooked up. He calls me and tells me that he misses me but then again we don't really talk that much. He is going to be transfered back to California in September and I don't know if he is actually serious. He told me that he loves me and that he cares for me. When he comes back its just going to be "us against the world". I don't know what to do because he has been known to cheat on his girlfriends and he cheated on one of them with me so I don't know if he is serious about it. What do I do?