Thanks for the input, Galagirl. We are practicing a primary/secondary model, and are not looking to make her a trio with both of us. Although he has expressed the desire to do a threesome with both of us, I don't think that she or I are up for that right now...not to say that it isn't an option down the road.
I have talked to him about what I felt my needs were. He stepped it up for a few weeks, and the fights continued, so he gave up. He stopped trying to do anything extra with me, and just did the bare minimum because he was frustrated with my behavior.
I think a main problem has been my reactions to all of this. I have been extremely jealous and insecure (thanks, that article looks like it has some good info). So I am trying to deal with that on my own. I have made an appointment to see a counselor to try and work through some of my insecurities.
I feel like he is not being honest with himself or me about his feelings for her. They could be just infatuation with her and the NRE, but that is still difficult for me seeing as how I wasn't really prepared for jumping into this, and the rapidness at which it has progressed. I wish that he would slow down on the progression with her. I have brought this up to him, but he did not say he would, and I don't know if he is willing to for fear that doing so will upset her or end it.