Should I confront my wife?

I think you should have a talk with her and tell her how much you love her and how much she means to you and why you love her so much. It will make her feel appreciated and want to be with you more and it will also make her happy to hear those things from you. Tell her sorry for getting upset earlier and that you know that you can trust her but don't mention the ex or anything. Once she hears all of this it really is up to her to look at her life and think of the right thing to do. If you keep badgering her about this guy she will just keep talking to him without thinking rationally just to get back at you. If you are really concerned, ask her sister or mother to bring it up to her and talk to her about it.