It's been a couple months since they got back together, and we've never stopped talking (just as friends now). But recently he keeps getting VERY jealous and annoyed when another guy hits on/talks to me when I'm with him, or if he's around someone I am hooking up with. He also always wants me around and asks me to go to parties so that he can see me more often, flirts with me, and NEVER mentions her to me at all.
I'm not interested in a guy who is in a relationship, but my question is basically why is he so jealous if he is with her? Is it a male ego thing or something else?