You have to remember...the OW is NOT on your side...she is NOT your friend. Telling her anything is not going to help. She is going to do whatever it takes to carry on the A with your H. She does not care that you exist.
As for exposure...when I first found out about my H affair...I didn't tell anyone...except for my mother, my H mother and sister, and 2 close friends. When I realized he was still carrying on the A...I told all of our friends, her xboyfriend(father of her 2nd child, just recently broke up) and his boss (since it was work related)...I think this had more of an impact...but it still did not stop the A from continuing. I think the fantasy of the R diminished a bit...but it did not stop the A. Just made it more difficult..and in some ways..may have fueled the fire. His boss kept it a secret..nobody else in his office knows of the A so he technically was still able to have his 'secret/illicit' A. Very exciting..ugh.
I have never reached out to the OW. I never wanted to give her the satisfaction..she is a piece of sh*t...not worthy of my time or reaction. The OW knew your H was married...she DOES NOT CARE!!! I don't see any point in letting her know.
On a different note..I would stop the intimacy..cake eating.
