As Kat said, you will not be making your son move.. she will. Besides, you've already mentioned that you may have to sell the house. So your son will have to move anyway.
I know you're afraid, but take a risk. Do a 180. How do you know she's not bluffing about moving out? Or she might move out and realize how sucky it is and then actually want to come home and work on your marriage... anything could happen... but right now nothing is happening because you are allowing her to walk all over you!
