Like I said, the OP has not yet had enough time to learn the lesson. Eventually she will and she will prove the ex right by leaving.

Yes, I think I'm one of the few people who think the OP should stay -- long enough to learn the lesson and get it once and for all. She doesn't SEE the reality of this man or the relationship yet. She wants desperately to believe what she hears.
Hopefully, once she gets it, she will get it and not repeat it again in a third or more relationship. The next time, it may take her 4 months instead of 8 to see through the guy. The time after that, she may realize it on the first or second date. Best would be to realize it during the salad course of the first date.
When I say that the man is a manipulator, I don't see him as being evil. He wants what he wants. Nothing wrong with that. He may truly hope himself that he can have a relationship differently this time and believe he can do it. But, PAST relevant behavior shows that either, underneath he really can't change this relationship, or he's too chicken **** to try to confront his ex.
What he really, really, really wants is a woman who will conform, change and fit in to what he and his wife have already shaped. A gf who can and is willingly to give him that would make everyone here happy. The wife will be happy, she's number 1 and in control. He's happy she's not ragging on him. And wife 2 is happy to comply as this makes DH happy.
In the current situation, WHO is the only person not FITTING in this scenario? The OP. Ultimately it's about FIT. If she really wants a relationship where she comes first, this one isn't it.
She also needs to learn the lesson of what her personal love triggers are. She obviously loves to HEAR how much she's loved. Follow through with ACTIONS and SEEING how much he loves her, not so much. The OP needs to learn about the
5 languages of Love. She will always need to have her man
tell her how much she is loved and reassuring/confirming the kind of life they have together. That is her love language. BUT, she needs someone who follows through on what he SAYS -- in the PRESENT, and not constantly talk about some nebulous future date where it will all happen.
Here is where anyone can take a simple test to find out what their/and their spouse/SO's Love Language is:
http://www.5lovelanguages.com/
Again, the OP isn't there yet. This is a good learning lesson though. I just hope she doesn't want future kids. The only problem I see is how much time it may take her to learn this lesson. If her bio clock is ticking, she will have that much less time to find her right love later.