I wonder what would happen to my S if he actually told his father what he thought of the girlfriend and his choices. I think he knows that X would probably pull what Carrie is doing, and make him choose, and he doesn't want to be put in that sitch. In order to have a relationship with his dad, he knows he has to keep it on a more superficial level, and vent to me.
I'm glad that T seems happier - she needs it! How are you doing?