My boundary is one that I feel very prepared to enforce. I just can't imagine myself not following through with what I've put in place if she crosses it. That is just how I feel.
Of course I would look at the specific circumstances and make a decision if that does happen. For example, if he were to call her and she talked to him. I may not go to the courthouse and file for D if that is all that happened...
Denver,
It might be good for you to think about this ahead of time, in the calm of the moment. To figure out how many "strikes" you are willing to abide. (One, but only if she self-confesses it? One, even if YOU find out she lied about it? Two? Three? Other?)
This wouldn't be something you would convey to your wife, but just to hold in your heart so that you don't have to make this decision in the stress of the moment, if or when re-contact should occur.
Just a thought; I'd seen that advocated elsewhere, and it seemed like a good idea to me.