I'd try to understand their state of mind. I would try and understand their relationship.

I would try and discern the truth from their partner without divulging anything. Then decide what to do.

That has happened and I did absolutely nothing about it. I decided that it was none of my business.

It depends on if they were honest about being wrong. If they cheated and made the cliche' act of blaming it all on their S/O, i'd probably just let them be.

Nothing. Truth always comes out anyway. I don’t want to be caught up in that drama.

I think the other person deserves to know...
Now if I know both are cheating, I don’t worry about it..

It's not my place to do anything, unless asked.

If it was in front of me or he/she came to me for advice, I'd be willing to listen and offer the available options on which course of action to take.

Depending on which option was chosen, I'd remain a friend or end the friendship. Tacit approval is something I was never known for.

not take sides you don't help anybody

86 them

I don't judge.There may be a relationship issue or maybe they are not the faithful type.Married men have cheated on their SO by having sex with me.

Stay completely out of it.

I'd say "Do it bitch, get that dick."

Mind my own damn business.