You know a friend's partner is cheating. Do you tell them?

Yes, absolutely. Your friend would want to know the truth, even if it hurts. Staying silent makes you complicit.

No, it's not your relationship. You don't know the full story, and getting involved will only create drama.

This is difficult, but I think you have to tell them. A real friend wouldn't let someone live a lie.

You have to tell your friend. If you know something this important and don't say anything, you're betraying their trust.

It depends on how sure you are. But honestly, if you're certain about it, silence is not an option.