My wife cheated, she was my best friend
I, at one point, thought my then-wife was my “best friend”.
Truth is, she never was.
She simply acted how she thought she needed to act in front of me so I would view her as ideal and would praise her as such.
It’s an all too common facade that narcissistic sociopaths put on and can maintain for many years.
Or, as long as she was getting value and validation from you.
Once they no longer feel that you are a source of that validation then they begin the process of devaluing you.
When they have found another source of validation, via an “affair” and betrayal, then they will go beyond devaluing you and into the realm of dehumanizing and vilifying you so as to create inward “justification” for doing what they very well know is a despicable betrayal and very damaging to many people.
One thing you must really pound in to your heart, mind, and soul is the truth that what she is doing and her reasons for doing it have NOTHING to do with you or your marriage.
Her reasons for her betrayal and irrational behavior exist ONLY within her and those reasons and her ability to rationalize it all have existed within her long, long before you ever met her.
I went through a situation very similar to what you have described so far.
I would suggest consulting with a lawyer to know your rights in the event of a divorce, protect your finances as well as you can, document everything you have discovered regarding her extramarital behavior, and then notify the wife.
Your wife is not your friend and, unfortunately, right now is your enemy because what she is doing is obviously hurting the very people she once claimed to care for the most.
Be prepared to see a level of selfishness and irrationality you have never conceived humanly possible.
But, it is critical that you remain calm as possible and secure with the truth that none of this horrifyingly irrational and selfish bullshit she is doing has NOTHING to do with you.
ETA:
She has been blaming you for her behavior.
When her affair has been exposed be prepared to be blamed for everything.
It is extremely critical that you immediately and emphatically flat out shut down any of her blaming you.
When it begins, just tell her “Absolutely NONE of this has ANYTHING to do with me. Period. I will NOT discuss or debate that whatsoever. If you feel like debating it, then do so while in front of a mirror.”
Then walk away.
DO NOT accept blame for even an instant.
For if you do, even just a little, you will simply embolden her and the irrational bullshit will increase exponentially.
[This message edited by keptmyword at 5:33 PM, February 27th (Saturday)]