I am just so jealous that you are still having physical contact with your H. Mine has barely spoken to me in the last year. I have a feeling OW has forbidden it. She has forbidden her mother from having any contact with her XH.
My H was, also, a wonderful father and H. The people who knew us were in shock when they found out we were separated. We were told often we were the perfect couple.
Everything happens for a reason, maybe Dad needs to find that it isn't better out there, he needs to realize how good he had it here. Maybe he will find God and that is the most important thing when he finds Him he will know he is supposed to come home.
