Posters go either way on this forum. I am of the opinion that IF the OM is married, his wife has a right to know her husband is cheating on her and by keeping OM (and your wife's) secret for them you both enable the affair AND become a co-conspirator of the secret.
If you and OM's wife were knowingly using the same accountant and you caught your accountant embezzling your money, even though OM's wife is pretty much a stranger you'd still tell her, wouldn't you???? Adultery is a far more significant and hurtful "crime" so I feel it deserves an even greater community consideration.
Others feel differently but I don't see how you have much to lose seeing that your wife doesn't look too excited to cut off contact all by herself.
As far as you being controlling, they all say that. I'm not suggesting vindictive exposure. Just telling the OM"s wife (if he's married) as the decent thing to do. Your marriage can survive your wife's anger. It can't survive, as you are coming to realize, as long as they continue to see each other at work....indefinitely.
If OM's wife "controls" her husband...all the better, but being "controlling" is not the reason you tell...it's to be, IMO, decent.
It's the RIGHT thing to do...IMO and no one regrets doing the right thing
YMMV (your mileage may vary).
Last point - what they call "controlling" today...if and when you recover your hopefully former wayward wife will then refer to such actions as "protective". You are FIGHTING for marriage and family here despite the devastatingly hurtful behavior of your wife. You are trying to save her. Being a stand up decent guy who is not afraid to stand up and do the right thing despite his wife's potential anger over messing with her affair partner is attractive and consistent with "letting her go". "Letting her go" doesn't include keeping her/their secrets.
The internet is 90% complaining and entitlement and I hate it because I deserve better!
