Well, it's been about 2 weeks since my original post.
I did my best to be open, welcoming, and tolerant of our situation.
Several actions that he took made me realize that we need INTENSE therapy, together and separate. I know the why behind many of the actions he takes (saying that his parents were a horrible example on how to have a loving relationship is an understatement. They openly cheated on each other and didn't hide it from their kids. At all. Not an open relationship, not poly, openly cheating. On top of that, I'm the first girlfriend he's had that hasn't cheated on him...and I ended up marrying him, warts and all) But, knowing the why doesn't give him a get-out-of-jail free card. And, you're right. He's VERY lacking in empathy. He can't put himself in my shoes in what I would think obvious situations.
One night, right after we'd had sex, he checked his phone and got a text from his gf. She wanted to go out for drinks...rather than saying no on his own, he asked me for permission. I almost had to scrape my jaw off the floor. Shock does not describe my reaction.
Needless to say, we had a long talk this weekend. Ok, so a 4-day argument. I poured my heart out countless times. All I REALLY want from him is to actually work on OUR relationship. I came to a pretty decent place with everything, and even got to the point where we all hung out and watched movies at our house (after the baby went to bed, of course). He was cool that I needed to chill out, to slow things down, and he did.
The straw that broke the camel's back? The day after we had decided to put the brakes on any external relationship to build our own, he asks if I'd be ok with him meeting up with a fuck buddy.
Call me stupid, but I can't just walk away. When we're on, we have an amazing love that I can't even describe. Which is why it is so heartwrenching to see this.
Which is why I've decided to seek out counselling before I make my last resort decision. It's probably going to cost a lot, but we NEED it. I think his view of relationships is BEYOND fucked up, and after reading and talking to people who have been successful with polyamorous relationships, I am positive he has a very skewed view of what means. I tried to get him to come here, but he doesn't think he'll be welcome after this thread *sigh*.