LO; I understand what you are going through. My W told me two months ago that she wanted a D, and was going to pursue a R with OM. He will not be local until much later in the year, so in the mean time we still live together, have for the most part a normal life (no ILY or ML), we eat dinner as a family, take care of kids together, help with projects, etc.
Early on, she would talk to OM on the phone in front of me and the kids, lots of other hurtful stuff, I told her it would have to stop, or she would have to leave, and it has. She cont. to talk to OM everyday, but not in front of anyone.
I have had the same concerns about having her cake..., but my W has never said she wasn't sure what she wanted to do. I have been thinking I have done a good job of detaching, I am supportive and continue to be helpful, so what is the reason to change?
Others have said focus on yourself and your kids and let them do what they are going to do, you can't controll it so don't waste time trying to.