Not ganging up on you, but Puppy is right here. By calling the OW, you are elevating her in importance. She is not worth your time, and you need to act that way. I understand your feelings and don't blame you. Just think contacting her is a mistake.
Take it a step further. Suppose you talk to OW and she flees like the scum she is. If H does not see the light, there will just be an OW#2. The problem is not the OW. The OW is just a symptom of the problem.