J.C.
This is really not about you or him, or how you feel about him. This should be about your child, what is best for the child, and unless the father is abusive or neglectful, what is best is having some kind of relationship with his father. You may not like this man right now, but you are co-parents of that boy, and he loves his father just as much now as he did before you broke up. Think about that child, how hurt he will be if his father walks (or is pushed) out of his life. You said you do not think the father should have any say in what goes on with YOUR son, but the fact is, that is HIS son as well, and he has equal rights, and has every right to go after 50% 50% custody if he wants, not just a few visits. Think about what is truly best for your son, and put any hard feelings you have to the side.