From your first post:
- He tells me that he made out with someone he works with.
- I got angry but was grateful for his honesty
- 3 days later I learned that this young lady was who he was interested in and they'd been talking for a while.
- He arranged for us to all meet, have drinks, and talk the situation.
- I had my objections, but for him I agreed to it.
Well, don't be in a rush to get all huffy at her. (Even if she behaves badly to you now.)
He is the first one who broke trust with you.
You broke trust with you second by agreeing to something you did not feel happy about.
So... are you mad at him? Or mad at self? Or both?
Kinda gotta sort that out.