Hi, lwb. Wow. What a day. I would not have had your grace.
I think you have an agreement with OW's H. You would want him to do the same for you. The note was one thing. Now you have another. I would call. Waiting 48 hours will let them squirm and give you an opportunity to figure out how you want to handle this.
The only reason not to tell her H is if you don't want to deal with the blow up that is bound to occur. However, her H is bound to find out eventually. Then what?
If OW's H leaves her, she will come at your H full force. She is well aware of her H's stand. She and your H are not trying very hard to hide things. It is very possible she is ready to leave her M. Tread carefully.
You have done everything right. The tough love approach may be a final tactic in your sitch. The A will have to run its course. They will fully have to deal with the reality of their choices. They will have to be responsible for each others needs.
48+ hours to consider what is best for YOU. You hold the cards here, my dear, even if it doesn't seem like it.
Me29 H33 D9 months S2 S9(previous R) Sep 8-19-07 I file 11-5-07 H home (Retro) 2-15-08 "Today is the tomorrow of yesterday." -- S9