I dunno about this situation. He sounds selfish and what he is doing just sounds like cheating. Why is everything on this third wheels terms? Why does he think he has the right to be jealous when he is screwing someone else? It sounds like your monogamist and he is being able to do what he wants. I would never let my man be with someone else if I wasn't able to as well. It's to double standardish. But I am new to all of this. But honestly that would kill me.
Your kind of getting walked all over honestly.