I tried to warn my X that his behavior would effect the way the kids saw him also. He inserted the OW into their lives as soon as he moved out (and apparently before he moved out also) then married her 14 days after we were divorced. D12 remembered some things, and has figured it all out and is disgusted. She loves him because he is her father, but she hates what he has done/continues to do. The kids see it, and they are affected by it. But the offending spouse never see it that way. they live in the land of "the kids will be happy because I am happy." Must be nice to have the world revolve around you!!! I never spoke about the things he did....I didn't have to, he made his own bed.....they all seem to do that.
Your X is who he is, that isn't going to change unless he does some work to change. The way he treated you will carry over into his relationships with the kids....it is sad, but it isn't your responsibility. All you can do it be supportive of your kids and hopefully having one stable parent will be enough.
"You can't stop the waves, but you can learn to surf." Jon Kabat-Zinn
