RF...how long have you and AJ's father been divorced/apart? How old is AJ? Forgive the questions, but it seems that you should not be fretting at all about this ex. He has obviously moved on, marrying again. If he doesn't answer your calls, why are you even calling him? Are the two of you still interacting in such a way that calls are necessary? Most people just move on, eventually.

By the way, I think it's very nice that, in the past, you have cooked holiday dinners and invited him and his new girlfriend. It shows that you are not emotionally bothered that he has new romantic interests.

As for asking you to fill out papers, is this something that requires your personal input for legal or medical reasons? If so , I'd just go ahead and do it, leave the papers outside in an envelope for him to pick up. If he's asking you to do HIS work for him re/filling out papers, just say you don't have time.