If your friend told you…

[Paperdolly]

If your friend told you she was having an affair would you share that with your husband?

Yes but I wouldn't remain friends with someone who does that anyway so I wouldn't be too careful about who in told. I couldn't continue a friendship with anyone who is that deceitful.

To add I'd keep a range of other secrets but cheating is a deal breaker for me with any relationship regardless if it's a friend, partner, acquaintance, etc.

100% not. We’re separate adults, absolutely no need to share confidences from friends in either direction.

This.

I'd tell my DH and I know all my friends would tell theirs if the situation was reversed.

If you repeat a secret to anyone , you are a blabbermouth .
Why would you think it's right to share something that a friend has told you in confidence.

I would, but then I know my dh is the soul of discretion.

I would, if I was upset about it, because I’d want to talk it through with him.

If she was cheating on an abusive husband she was scared to leave, I’d probably keep quiet, privately disapprove of her choices (leave first, then find someone new, not the other way around) but support her.

If she was single and sleeping with someone with a family, I’d disengage and distance myself from her, and probably talk it through with DH.

If she was cheating on her husband that we knew, I would probably be angry she put me in that situation and wouldn’t engage at all. And would probably tell DH why.

Good people don’t cheat. I like to be friends with good people. I would find it hard to move past that, it’s such a hideous betrayal.