Ignore it and even if your wife ends OM1, she will very likely end up with OM2.
I have never seen MWD advise to simply ignore an affair. I believe what she teaches is, you can't spend all your efforts attacking the affair and fail to work on your own issues, or else there will be no "better man" for your wife to come back to, even IF she decides to return to the marriage.
The "Little Bo-Peep" approach doesn't work. Affairs are highly addictive, and I don't know of ANY addictions that just go away on their own. In fact, most escalate.
