Little Bo-Peep refers to the whole "leave them alone, and they'll come home, wagging their tails behind them." Since affairs -- most believe -- are ADDICTIONS, and since addictions tend to ESCALATE, rather than die on their own, I don't believe this is an effective approach.
Now, if one wants to say "I'm done; I'm letting you go," and MEAN that, that can -- ironically -- WORK. But it's naive to take a stance of "I'll just not address the infidelity, because it'll just die on its own," because I've never seen ANY addiction behave on that arc.
