Try to keep as much about your life and that of the boys confidential. If he starts acting out, get an order of protection so that at least the issue is documented. I would seek the supervised visits right off the bat. That may serve as a deterrent since he balked at it the last time. Just remember that whenever you move on with your life (which you have) they get angry or bitter. Whether you forgive the arrears or not, he will act out. SO, with that said do what you need to do to stay safe and to protect your kids.