I wouldn't say anything about the OM or the dating sites. You are sure she has an OM, and you are worried about her being on dating sites? Seems odd.
If you do it, just know that confronting her will not help in reconciliation. As said above, there will be no "come to Jesus" moment for her. I think you should just assume she has an OM. Then, your decision is: if she is having a PA, is that a deal breaker for you?
You are struggling with detachment. You really need to focus on that. Get to a point where nothing she does affects your emotional equilibrium. You're going to have a kick ass life either way.
Detach, GAL (stay active), 180s (work on the things that need working on)
