If she is openly discussing dating that is pretty clear that she has checked out of the marriage. I think you are right to push her out. I can understand your ambivalence but at the same time that type of attitude on her part is not that far off from an A. She doesn't respect you or the MR.
Me46 W46 M25yrs T29yrs 4 children ILYBNILWY 1/30/17 PA confronted 3/6/17 Separated same house