Absolutely, do not go to his house to visit the kids. I know you want to see them as much as possible, but by going there, you are in a way sanctioning the situation. Let them come to you, or meet them at the playground or some other fun place.
If a man who was abusive during their M can poison her mind against you, then your W is truly lost to you. If she is still "in love" with you and is just very angry, then your staying away, going dark, will benefit you. Her X will show his true colors soon enough, and then she will remember how it was with you and the contrast will be obvious. She is probably remembering the better times with her X, and thinking it wasn't that bad. Just give her the space to see how wrong she is. In the meantime, practice being calm, patient, and in charge/control of yourself. And don't just give her full custody in the hope of getting her back, or because she stupidly gave her kids away in her previous R. That doesn't mean you should be as foolish as her. Get at least 50/50 custody. Fight for your kids. Your are their dad ... she left ... why should you be the one to lose them. Makes no sense to me.
What Coach says.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim