I have to be honest, I would definitely want to know.
But why are people being shitty to @Blossomtoes because she feels differently.
Once you know, you know. There's no going back and people often say they wished they hadn't found out.
And I do agree with Blossoms 'polishing their halo' statement. Most people don't tell the other woman, for her benefit. They do it because they have another motive.
I believe in ops cases, ots so she can feel she exacted revenge on a cheater, because she was cheated on by someone else. Its not an altruistic deed.
When the OW wants to the girlfriend or wife, it's usually because they want to cause the most amount of pain. Which is why you get alot of OW refusing to give details, then giving them later, but not all, then giving some more and dragging it out. They don't care about how the wife/GF feels. They care about causing him the most pain and the wife/gf is just collateral damage.
Or the hope the wife/gf dumps them to the cheater will run back to them.
Again, it's not an altruistic deed. The person telling usually gets one gain out of it and just see the wofe/gf as a pawn to get whatever they want.
In all honesty, if dp cheated and the OW knew about me and then was pissing me about. I wouldn't leave him. I would spend time getting everything ready. Make sure he makes sure she absolutely knows she means nothing to him. And then when he least expects its, I would make sure he knows he means nothing nothing to me and get rid then.
But then I can be really spiteful.