What does he really want from me?? Please helplpppp I don't know what to do?

Sorry this is kinda long. Okay so this guy and I are like best friends kinda and we can talk about anything. He's known I've liked him b4 and all that and he's liked me b4 but we've never dated. Hes had two gf's in the past year and still with the second now. And the other day he wanted me to be a friends with benefits with him after his relationship now. And i said I'd rather be a couple and fool around then be friends with benefits(fwb) that it would have more meaning and I would be more willing to if the guy I was sleeping with was my bf not a fwb. And he said that he doesn't want to date me bc he is good friends with my brother and that he doesn't want to mess up everything we have together. But the other night he was wanted me to send a pic and I said why he said bc it's not fair you keep the amazing body hidden from me since you see mine all the time( he plays water polo hence a speedo hence we seeing his gorgeous body) anyways he was saying stuff like that but I said no bc of his gf. And he said that's true undone want to cheat on her but we already agreeded it's not cheating for us. And so idk what to do. I wanna go all the way with him but does he just want me for ?? Please help meeee!