Why do I feel so guilty for wanting him for ?

Went out with this guy for 10 months; not a real relationship, just if we both had time, etc. We contacted one another about once a week, back & forth. We started seeing each other more & I started to like him. Couldn't tell how he was feeling but anyways it all came down to me finally telling him what I was starting to feel & he said he liked me too but I could tell he was freaked out. We went out for another 6 wks or so & finally I told him I liked him again & he said that he liked me but he thought I was teasing him & that he was a "typical guy"(?), which is okay with me. In this dicussion there were some tears &some hurt feelings (on both parts) I didn't speak to him for 8 wks afterward just trying to forget him. Problem is we had MIND BLOWING (we waited til 6 months to do it) & I can't quit wanting that part of it! I want him to be my FWB but I've never done that before (have txtd several times in the last 2 wks but I am feeling guilty about just wanting him for that only)