How do you avoid becoming a friends with benefits relationship?

I met this guy that I really like and we had one date. I felt like we really hit it off so we messed around before I went home that night. Now I am back at school 2500 miles away. We still text and stuff but he only seems into the conversation if it is about ual things. He has said that he wants to hang out when I get home but I think he just wants to mess around. How can I turn this around? I'd much prefer a relationship with him over fwb...