Most Helpful Guy
honestly I think ya already know what the right thing to do is. don't. cut him off, block his number, stay away from him and tell him to figure his marriage out. He's prolly gonna mess it up anyway but don't let it be because of you. find somebody else who is single, until ya do it really doesn't matter how bad you want this guy you can't wreck his life. masturbate or whatever ya gotta do to calm down but DON'T fuck him :/
Most Helpful Girl
Ask him if he's done it before outside his marriage. Usually not a good idea as he'll leave you hanging and you'll be attached. It's nice to not have awkwardness with people you've never had sex with. Who knows, he could have stopped having sex with her, but usually Pandora's box isn't worth it.