Your W doesnt love her OM, she is infatuated with him and you have been paving the road for her to continue to deepen her affair. Has she faced any consequences from this? Then she has no reason to stop.
Her state of limerence is what has caused her to detach from you and her children. The vast majority of the time WW will eventually reattach with her children - could be a few weeks, months, maybe years. But always well before she re-attaches to her BH.
If she is really willing to give you primary custody right now - you absolutely have to lock this in because she WILL change her mind. I've seen this too many times to count. WW is in la-la land and will give any concession to feed her affair addiction, the BH comes in to see me but is paralyzed out of fear and love. Invariable, reality comes crashing down on WW and she blames all on BH. Then she starts with any weapon she has, insults, bad-mouthing, false accusations, RO's, stealing money, parental alienation. Now the BH is on his back foot, facing every-other weekend custody, 60% of his salary on alimony and child support and everyone thinks he is an abuser. And now he hates his WW, and is kicking himself for not doing something when he had the chance.
Consult an attorney and then either file with them or file yourself immediately. This doesnt mean you will get a divorce, this means that you are in a position of strength - you will control the pace of the petition and you will hold the cards either in an eventual divorce or in a possible reconciliation.
She may seem all but possessed right now, but her short duration, long distance affair will likely crumble when she starts seeing some real consequences. The prospect of losing you AND her children, on legal documents and in physical reality is a very real consequence.
