"H has acted like a guy that trashed his room--threw his dirty cloths all around, left dirty dishes everywhere, then looked around one day and said, "this room sucks, I'm moving to a new house!" instead of just cleaning the room and improving his environment. "
Your son has obviously acquired mom's ability to articulate thoughts into easily relatable word pictures. I couldn't have said it better myself and I can easily relate to his comment.
Excuse me for continuing to refer to your relationship as a marriage, but to me the dynamics are the same and so are the problems. I understand your feelings about his not committing to you legally and that you are being deprived of the security and benefits that often come with it. I know that I would feel the same way.