I don't have answers for this question, but I'm going to throw it out there anyway:

If you set a boundary of no OM contact while you're working on your M, and she goes and has OM contact anyway....

What's that mean for your boundary?

I know the DB coach suggests doing what you can so that OM doesn't have impact, but you laid out a very clear expectation of something you would not tolerate (you're not telling her what to do, you're telling her what you won't tolerate). If she pole-vaults over that boundary....it's disrespectful and tells her you'll put up with her stepping over your clearly delineated lines.

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