Could you consider middle step between (staying there watching the wacky) and (divorcing and leaving entirely)? Like a trial separation where you move to your family to have the baby? So you are at least free of watching the wacky up close and personal?
In that time apart who knows? Maybe he comes to his senses, the GF leaves, you and he patch it up, the trio stabilizes, it becomes more clear that you need to split, etc.
Many things could happen - but they need time and space to happen IN.
A trial separation could be helpful for making that time and space to have things happen in, for rest, for giving birth in a calmer way, and for reaching clarity before embarking on any permanent life altering decisions.
In your other threads? To me your husband does not seem to take personal responsibility. When he "suffered" with you dating your BFs, he blames you rather than the situation, a situation he chose to enter when he agreed to non monogamy. When you make reasonable requests to find a house first before dating, he blows you off and continues to blow it off. Which is him not managing his marital relationship and taking personal responsibility for helping with its healthy upkeep.
He is presenting you with "like it or not, YOU deal with it!" right now.
- He WILL NOT participate in the marriage in a healthy way to solve problems and resolve conflict. (You were not even saying no -- you were saying finish the move, get home first.)
- He WILL NOT take personal responsibility and help file a divorce if he no longer wants to participate in the marriage in a healthy way.
- He WILL fob it all on you to deal. This is all kinds of fresh to me.
If you guys are still living with her and there still isn't a separate home for you and husband? Could present it that way:
"We need a time out. I am going to AZ to live with family to have the baby. That let's you and X have space to date free of fuss. Let's you have time to find some home rental potentials. I can fly back to look at them together when you have narrowed down top 3 and sorted out your VA check."
He either starts getting responsible, or not. And you get some distance to evaluate that more clearly despite your emotional ties. As well as time to research which of the states is better to file in if it comes down to that.
Boil it down to
behavior done/not done. He steps it up on finding a home so you do not all live together crowded or not. He steps up, you come back. He does not? You think about moving on and filing, not just researching.
Try to remove the emotional component entirely even though it can be hard.
Distance is good for that.
Hang in there,
Galagirl