How are you wording "over my dead body"? Are you saying it like that or are you saying, "You can make the choice as you see fit, but this is my boundary and...."?

She needs to get that it's HER choice. She can see OM if she wants. She cannot see OM AND work on her relationship with you.

ME: 38
BF: 40
T: 10y, no kids, no M (by choice)
BD: 7/14/14, BF admits to PA, wants out, lies about new R.
10/1/14: I move out, BF lies about move in with OW
12/4/14: OW confronted, reveals all the lies