Look, this is how marriage works, if one spouse doesn't like the other spouse's friend, then the friend has to go.
That means the spouse puts the marriage before the friend which is how it should be. I don't think your wife would do that.
In general, I am in full agreement. However, I also see the merit with what Sandi2 has said to me relatively recently which is that laying down the law WRT to her bff at this point is only liable to push her away and back into rebellion... that at some point as part of her "recovery" she needs to understand that relationship with bff is not a healthy one and that bff's lifestyle is not consistent with W and I having a happy, committed, and complete marriage. Sometimes I think she is close to "getting there", as when she pretty much cut herself off from bff for nearly a month, or when she said she was "reevaluating all her friendships, including with bff". Then, other times, as in counselling (although this was VERY early on in counselling, when she was still actively seeing OM) when MC suggested that friendship needed to end and W later said to me "well, THAT aint going to happen." BFF is pretty much her lifelong best friend... not that I think for one moment that that should take precedence over our M or even be allowed to impinge on our M but... it's a relationship she is not going to give up easily, and I am not sure it is in my or our marriage's best interests at this particular point to be pushing her on that issue myself. Maybe if she were to get into IC (as she has said repeatedly she needs to and will but to date has not) the IC/MC can promote that idea a bit more.
You know what would really make me feel better/safer right now would be if we were to start wearing our rings again. Of course, I effed that up by losing mine. Not to mention which I had been wanting to save that for renewing our vows, etc., if we ever reached that point.
H53/W51, R-ing 4/'18
"Do not arouse or awaken love until it so desires"-Sg.of Sg 2:7
"So oftentimes it happens,that we live our lives in chains, & we never even know we have the key"-Eagles III 1:3