This is so close to my story it's crazy. I didnt catch them in the act, but I had the friend, who was the wife my ex-wife's new guy at the time, sit down with me and go into a long, well supported tale of what was going on.

Took 2 years to divorce. It too was clean (thank god). At the end of those two years. During that time I went through depression, and now have sympathy for people who are depressed in ways I never did before.

I met my current wife of 19 years at the end of those two years.

You are going to be fine. Keep her out of your life totally. Not even a little regular contact. It should be an odd awkward moment if you two happen to see each other at a target (happened to me).

I wish you well.