What to do when you find out he is cheating on you ?

saying he loves me...but still has a wife, answered his wife phone to which he claims he doesnt live anymore but at 5am in the morning when they claim to work nights they answered her phone...hmmmm do i call back and confront him, or do me and let him sink himself, or call back and speak with her...now im angry and really pissed off....dont tell me you love me and you sleeping in her bed, WOW!!!! I can already tell this is going to be an interesting weekend.