Are you sure he isn't experiencing a medical problem, like alzheimers or depression? There's no reason why a 65 year old senior man would revert to a child unless he was actually experiencing some form of dementia. I would probably bring him to a doctor if I were you. That was my first thought after reading your post. Anyways, if I'm totally off here and wrong, then you may want to start distancing yourself if you dislike being around him. Try to be happy next time you see him, because I'm sure your reaction to him would trigger an argument if his very presence sucks the energy out of you. Try to think about things other than him when you're hanging out with him - in other words, try to lighten the mood. If that doesn't work, then live your own life away from negative people. If his wife is helping him, then it isn't your job to fix anyone if they don't want to be fixed.