This is THE #1 place where people blow it, FFH, after months (and sometimes YEARS) of all of the hard DB work. DON'T SCREW IT UP NOW.
You need to tell her that YOU do not feel safe in the marriage with her friendship with OM, and that she needs to end all contact with him and agree to full transparency -- "just friends" or no. If she fights you on this, conversation's over. Do NOT get into a debate or an argument with her about the degree to which he was a "friend" or an "OM" or whatever; in fact, ASSUME he is just a friend, but that your wife has up until this point decided to put her friendship with someone else ahead of her marriage and her husband's needs (and she has). If she can't put your needs and fears FIRST, then you don't want to remain married to her.
Calm, polite, and full of "Hey, I COMPLETELY understand if you don't want to do this, but you asked me what it would take, and these are it." NOW is the time to present your short-list of "dealbreakers," your Boundaries of Personal Integrity. They might be:
1. Send no-contact letter to OM, the copy of which is to be approved by YOU and it's to be MAILED/DELIVERED by you (so that she adds or subtracts nothing from the approved copy).
2. Full transparency. She changes her cellphone # and e-mail address(es), and you have access to the detailed billing of the new ones. She keeps her cellphone unlocked, and you can look at it any time you want to. She lets you know her daily schedule for a period of time, and calls you periodically to let you know she's on her way home, or going out with friends, etc.
3. Marriage counseling, or perhaps a Retrouvaille weekend?
4. ??? For me, it was "a full-panel STD test, with the results to come to ME," but my wife had had a full-blown PA. This may be something else for you.
5. ??? For me, it was that she had to quit her job, because OM worked there, and they'd come into daily contact.
I wouldn't do any more than 4-5 of these, or they'll come across as an impossible-to-achieve list of demands. They should just be those few, core Boundaries of Personal Integrity for you -- what YOU need "in order to feel safe in the marriage again considering the recent events."
FFH, I can't emphasize this enough: do NOT debate the list with her, and do NOT compromise on it. It's 100% "all-in" or it's nothing at all. Screw this up now, and you'll regret it forever.
Puppy
P.S. For the record, I don't think she's sincere. As you state yourself, I just think she's afraid. She's not liking the fit of the Big-Girl Panties.
