MuddleThrough, I think GH is right. Just tell her without explanation. I think you have clearly let her know before your misgivings about this trip. No more needs to be said. As GH says, you are going to be the A-hole anyway. I don't think the moral thing will fly or have any impact. She thinks that she is unhappy and therefore has moral right to be happy. That is that. (I told my W she was morally wrong and to do the decent thing and move out! It was a snit and a poorly planned manoever, she's still here) Anyway, I know I sound like a wimp here but I would be inclined to let her go. She needs to know whether this is real or not. I also know what a horrible feeling it is to know that your W is flying off to be with someone else, it tears your heart out. I just don't see how your moral stand will do any good for your sitch. But again, what the heck do I know. You have said before that she sees you as a bit too timid etc. and maybe putting your foot down is the right thing to do. If you feel nows the time to take a stand, then go for it. I'm stumped. Make a good decision that YOU can live with. My thoughts are with you.