My H was also immobilized as you put it. From the start of me finding out about the affiar he would say that he was not in it (affair) for the long run. When I sould say to him go live w/her since she make u so happy he would say thats not what he wants. I gues he only wanted the new sex partner ( he said we got old in that department). Really all our fighting mad it get old. It took 4 me getr really Bit*** to him everyday telling I wanted him out so he will leave ,he did little by little.
My h use to not want to be like his father (alcholic & also a big time adulterer).BUT the difference btw the two is that FIL did not leave not even over the weekend from their house when H was growing up. FIL left way after they were grown.