I don't want to make this too outing but will try add as much detail as possible.
I have been friends with this girl since we started an apprenticeship at a big company seven years ago now. Where we've both remained at the business.
Her boyfriend who worked there became her fiance, they bought a house and booked their wedding, which I was a part of. One day she came to me upset, almost of the blue saying she was to leave him because he kept being verbally abusive to her and she didn't love him anymore. I supported her unconditionally and allowed her to stay with me until they sorted the selling of their property etc.
Whilst staying with me she told me she liked the look of someone else at work, but he was with a girl and had a baby? I told her it was wrong. I later heard she'd tried to message him multiple times. I never said anything to her but it made me questions her morals.
She is an attractive girl and got a lot of attention so the gossip that she was trying to message multiple guys throughout the business was everywhere. She eventually ended up in a relationship with a guy who works alongside us and they were happy, lots of holidays, she bought her own house she couldn't stop praising him enough to me and I equally thought he was lovely. He also played a sport with my fiance and we went on lots of double dates etc.
Until recently she confided in me she had been messaging a married, older, manager. I was in shock I told her she needed to stop.
This manager left his wife, next thing her boyfriend has found out (believe he went through her phone) I actually find out she has been sleeping with him. She never told me this, my fiance did.
I confronted her and she insists they hadn't slept with each other until he had moved out of his marital home. As you can imagine they're the talk of the place, she has insisted she had major problems in her relationship and he was controlling. I really want to distance myself from her and her behavior, I feel so sorry for managers wife my DM went through something similar, but at the same time should I be judging her when I'm meant to be her closest friend. I would miss her a lot.