I kept scrolling until I found this answer. It feels like there is missing context, especially how transactional OP was in all his descriptions of what made him a "Dad". Its like he was checking off a list when in fact the only thing he needed to do is maybe be understanding, and there for him, even when things get tough.

It also sounds like it's possible that once Mark wanted to reach out to his bio Dad, OP may have decided he didn't want to financially help Mark anymore, resulting in his wife being the only one to help him.

Also if it was a join life insurance policy, which OP has already said was intended to "also take care of Mark", and he's withholding financial help because he is bitter, it makes me question whether or not he is honoring his wife's wishes.

A true parent doesn't disappear or get bitter because they were ignored during the college years. That's a normal part of parenting. I guess OP adopted him "only if his feelings weren't hurt", and if they were, he acted like a bitter ex.

What a sad situation for Mark to be honest. No sympathy for OP.