Friends With Benefits, but am I in love?

It's been about a month since me and this guy have been having what we call "playtime" and I am having strange feelings. He says he likes me, but I just can't shake the feeling that it's a lie. I feel like one day I'm gonna wake up and it's gonna be a dream or some sick joke. I think I really like him and I honestly don't think it's because of the sex. I think it's because of who he is. What do I do?