Around 7 mos ago, I told my W that as long as she was in a relationship with OM (which she denied), I didn't think she should stay at the house. No way did I ever think she would actually move out, but she did. I think she realized that this was her decision and that it wasn't healthy for either one of us for her to remain at the house.
Obviously you know your W better than we do, but maybe she would agree she needs to be the one to leave??