Has anyone told the OW's / OMs partner?

[rosabug]

Hello. I was wanted to know of any experiences where you or someone you know has told the OW's or OM's partner about an affair? What was the fallout?

I have been in this situation and I did not, but I often wonder about what might have happened had I done so. I'm not really looking for opinions about it, because I have heard many - usually falling firmly on one side or the other, but hopefully experiences.

I had the opportunity to tell the OWs partner but didn't. I had nothing I could really offer him as concrete proof and the OW was an absolutely fabulous liar and one of these people who come across as sweet and lovely. She would have denied it successfully.