I think that you just need to write him off. If he wants to come to celebrate a wedding or birthday or something sure.. let him but don't even let him in your heart or mind. He's just a loser and he has no idea what he's missing, neglecting his children all this time. he's not worth your time or effort at all.. Heck I'd go as far as saying this post wasn't even worth your wasting your energy on him as much thought as it probably took focused on him! Yeah, keep a distance and if he comes around, put on your "thick skin" armor.