Well, I hate to tell you this - but it never gets better. But eventually - your ex MIGHT get the message - that's all.
My ex left over 10 years ago and moved in then eventually married his affair partner. My children (then in their teens) wanted absolutely nothing to do with her. And still don't. And could not be forced to.
My son met her once. The night he realized she was living with his dad and he confronted them both. It was BAD!!! He won't go near their house and their dad knows in no uncertain terms that she is never to be around him.
My daughter was turning 13 when he left. We tried to protect her from "the truth". Then dickhead ex just let it slip one day. She was heartbroken but also refused to be near "maggot". (ow).
Ex has always insisted that I influenced the kids in their decision to not have a R with her. Never gave them any credit for having the intelligence or the right to make up their own minds.
Ex took D to his house on a visit one night after he had bought it - told her no one else would be there. She told me she was uncomfortable. Then another time he insisted she stay there while he fixed her car but that maggot would be at work. Again - she was uncomfortable. Recently he was extremely ill and is semi disabled at present so she went there to visit him (he agreed that maggot would not be around). She told me it was strange to her and uncomfortable with photos of her and her brothers in the room and some of her childhood home decor pieces around. She doesn't want to go back again any time soon.
Continue to support your daughter's in the choices they make. Let them tell their dad how the feel. Ignore the stupid things he says.
Last year my son told me his dad talked to him about moving fwd and leaving all the crap in the past and that he wanted him and his sister (other son is severely disabled and can't make the choice) to accept them and even to have holiday dinners there on occasion. I told son that it was his choice and I would support his decision no matter what he decided. He just laughed and said "No way!!". Although he feels some guilt about not spending much time with his dad.
It is SO difficult. But the kids did not choose this any more than we did. All we can do is love them and be there for them.
I think my ex is finally starting to realize the mess he made.