I don't know why people are asking "what will it accomplish". It seems obvious to me. Your W is indecisive. She's got a parasite of another man "divorcing his W for her". She's not going to make a decision to stay in the M until he's gone.
Women go into affairs because of low self-esteem and to fill something they feel is missing emotionally in them. All of her emotions are now tied up with this OM. She's not going to think about coming back until something happens.
Well I can only speak from experience. I confronted my W's OM who happened to be her boss. Once I did, he scuttled back to his W, said he never really had feelings for my W (despite what he told her), and practically wet his pants. Once he was out of the picture, she could concentrate on the family. He was a distraction.
She told me that by doing that, she got back a whole lot of respect for me because it seemed like I cared enough to save her from a big mistake.
But if you don't mind another guy messing around with your W, that's up to you. I didn't want a parasite next to my W whether or not we got back together.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.