Ok, this is not good DBing. I'll tell you that right off the bat. But next time you exchange DS and the whore is there, I would do something like this (making sure DS can't hear of course)...
Walk up to her. Calmly, very calmly. Say "I just wanted to congratulate you. Trapping a man into staying, classic but not very original. I wonder though...just how long do you think he'll be faithful to you? Or that's right, he already cheated with me. "
Then walk away. It's even better if you can manage it so that H won't be near.