I understand where you're coming from. I only came to fully realize as a parent, how truly awful parts of my childhood were. And it made me hate my father even more. Now, I don't hate him but I don't like him either. I feel no more affection for him than I would for the guy sitting next to me on the train. Yet, I still fake my way through these visits. I often ask myself why. Not much advice here but I definitely restrict his access to my kids. He's not a good example and my oldest has begun to notice what a dirtbag he can be and how selfish he is. Do whatever feels best for you. I wish you luck and peace of mind.