Friends with benefits

So I met this guy at work, who I became instant friends with. We just clicked for some reason, and have never looked back. Well we use to spend a lot of late nights in my car talking about anything and everything, and from those talks, I started to develop feelings for the guy. I knew he was feeling the sexual tension part, but I wasn’t sure if he felt the other part that I was feeling. He has a girlfriend, though there on a break right now and to be honest I don’t think they’ll get back together. But him and I had a talk and he see what him and I as just sex, because he still believes that he will get back with his girlfriend. After hearing what all has happened and how little they talk now and stuff I personally don’t think they will, but no matter what I tell him to remain positive and I support him. He has called me cutesy names before, and he cares about me and our friendship. He’ll come if I need him and he makes sure I’m ok. Does anyone have any ideas that I could maybe use to make him see that maybe the girl he’s on a break with may not still be the girl for him, and the one he has sex with may be more than just a friend with benefits?