Does he have hope of a future if he has a controlling ex-wife?

Hi. Recently, very recently, I was with a man who is divorced with the most adorable little girls (outside of my own of course). We'd been together on and off for a year...off due to what has become clear was the influence, guilt and control his ex wife has over him.
I know some of you will say that I'm speculating, but after he called it off this last time, I confronted her. "Why did you confront her?" you may be thinking. When it ended the first time, it was a month after he had all of a sudden moved into my house because he could no longer live with her (long story short - they separated, stayed living together for their children). He'd still been going to counselling with her to make sure they were still keeping things ok for their girls while he was living with me. And during those sessions, she'd always throw out the "I'm afraid I'm going to lose his friendship" card.
They had children, the separation was amicable. Their friendship wasn't going to dissipate, and I'd never made an attempt to cause it to fall apart. It worked for them, and more importantly, their girls.
During the last session, while he was living with me, it supposedly came up that I'd not given him a key (I was home all the time at that stage), there was no storage for his clothes, and he wasn't getting his mail to my house. He hadn't asked for a key, we'd been out shopping for storage, and his mail is not my responsibility.
So skip to now. He's in his own house. We'd gotten back together. I'd been studying. Helped him move in and locate furniture, helped put his girls bedroom together, he'd started hinting to me and my children that we'd get married one day...things were great. Things were great despite the stress of my study and him moving house away from his girls.
Until his daughter's b'day, and his ex looking at us (my children and I) like we were lepers, no hello or anything when we walked in. She made it very obvious we were not welcome. So with me left to sit away from the party, the party he invited us to, the last thing I wanted to hear from my now ex bf was "How's the burger?" when he finally came to talk to me. I said "Yeah, it's great" and told him to go back inside with his family, so he stormed off, said nothing. Not wanting his ex to yet again listen into a private conversation, I had to lean over to him sitting down to ask if he wanted us to leave. We did as he wanted, and left.
So when I confronted his ex, a lot of stuff came up - she said me not giving him a key was abuse despite how short a time we'd been together and him not asking for one, she'd accused me of being abusive when I was asking him if he wanted us to leave even though she couldn't hear what was said, she'd said she didn't think he wanted to be with me despite him hinting at marriage, and she said she'd let him be with someone without trying to control everything but not with me.
I know that unless he stands up to her and stops pandering to her, there's no chance for me.
But my question is, how the hell do you deal with that? And does he have any hope in finding someone that she'll let him be with?