now she's planning something for the family to go away for the weekend. I
So, give her a reality shake up. She no longer gets to plan something for the "family" b/c she has torn the family unit apart. She no longer has the privilege of planning anything that involves you.
You have to be the strong one here. It's just like when as a parent we have to be strong enough to see our kids experience certain things so they will become a responsible adult. As much as we might want to cave in to emotions, we know they will not develop and mature the way they should as long as we give way to them having what they want all the time.
I have observed how many LBH'S of a WW will not stand up and tell her "no". He will not take the reigns and start doing the hard stuff that will show her the reality of her decisions. It's not enough to just be against what she wants, he has to do the action that shows that she doesn't get to call those shots now. She can't move out and then continue playing family.
Let's say that this ends in D, and the two of you eventually marry someone else. Would you and your new W and kids join her and her new H to act like one big happy family? Would you take trips together and celebrate each other's birthdays? Well, IMO, that is the reality your WW needs to see.
Sure, you can go on this trip together......but I think you will be disappointed in the outcome. You will be hoping she sees how good things can be and it will cause her to end the A, etc. However, she will be there for what's in it for her. Selfishness! She uses the kids as her leverage, and that's all. She will not be seeing this as an opportunity to repair the MR. It is pure cake eating for her.
If within the next four weeks, she ends the A, stops all contact with OM, and you can see a vast u-turn in her attitude and actions.......then you can re-evaluate things. However, if she seems to have a last minute change of heart, right before time to take the trip? I wouldn't place much value in it.
It is astonishing how the WW thinks she can still call the shots and the family will continue carrying on as though her leaving has no effect on it. It goes to show how unrealistic she is thinking. IMHO, the sooner she sees the reality of what she has done, the sooner the fog will begin to break.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!