Am I a horrible person?

Am I a horrible person for having fantasies about my best guy friend. I'm not even attracted to him. I just watch him treat his girlfriend like a princess (and she doesn't deserve it) when my fiance isn't even remotely nice to me. Nor does he clean up after himself or even have sex with me more than once a month. He is always looking over my shoulder and never let's me out of the house. But somehow I feel like the bad guy for thinking about this other person.