Man, I feel for you. You are in a tough position. I go by the proverb, a man who believes but does not do, does not believe. You need to decide what your core beliefs are and then act on those.
First. You did not cause this situation. You are merely giving those without agency, their agency back. It always seems to be the perpetrators of chaos that think knowing about the act is far worse than committing it.
I am ex military, and I have four core values: duty, honour, loyalty, and integrity. I try to make all of my decisions based on those four pillars. If there is someone in my life that would cause me to break on of those, I excise them, not out of malice, but because I cannot exist authentically without my core values.
My EXWW's BFF knew about her A, and I think passively enabled it. My MIL thought that she subconsciously fed off the drama. It was only when she and her sister walked in on a session that she was forced to confront the dissonance between her perceived values and her actual conduct. You see, my EXWW's BFF saw herself as a deeply moral person, yet she enabled behaviour that was amoral. Being weak, she could not confront, so she told my BFF.
My BFF then called my WW and told her that she had one week to confess or he would travel to our city and blow up the A. My EXWW begged, pleaded, and negotiated, promising the stars that she would change. He said one week.
In the end, she confessed but lied. I have cut her BFF out of my life as she lacked the integrity to remain in my circle. I tried to R but chose D for the same reason.
You need to tell the truth for you. How others react is up to them. You didn't ask for this burden, but it is now yours. Just because it has been thrust upon you does not mean you must carry it. Good luck.
[This message edited by Justsomeguy at 5:45 PM, Sunday, December 3rd]