Why does she keep telling you, for 13 months, that she wants a divorce? Can she not file herself?
She is detaching from you and GAL and dressing well and that is what you should be doing as it obviously works.
If your W wanted the kids for her bday aaashe would have asked IMO.
As far as an open marriage, you can only control whether you stay in the marriage or not. You can't control what she does. Figure out what you want to do.
H 34 W 29 BD 3/12/18 Divorce Busted Spring 19
It is not things that bother us, but the stories we tell ourselves about things.
