Sand,

Now is when you sit back and stop the pursuit, stop the R talk, no negative talk about OW (that will only make you look bad, not her).

Let her hang herself. She has enough rope with the mailing of the papers behind his back.

Step back and let her do the pushing. Let her try to control him. Say nothing else about her or the situation.

Act "as if"

No expectations on what will happen next. Just pray that God's will be done and then drop it.

BFM

There is only one person who could ever make you happy, and that person is you.
David Burns, Intimate Connections