Well, I handled the OW well the second time. Yes, there were TWO parking lot incidents. The first one is when she came out and told me about the EA. The second one (five months later) is when he had ended their R but she stalked him and came out of the darkness in the parking lot to say he had been having sex with her. Yup. This OW is crazy.
Good idea to get the STD test. I did it, and the lady who did the test told me she had THREE people a day who were there for the same reason (spouses with affairs.) Can you believe this?
I think you and your W are on a good path. Remain patient. Remain taking care of yourself. Remain calm.