WW in PA: Threaten to tell kids? Confront OM?

[hoosjim]

Another question regarding my stance with the kids when I "drop the bomb" on her: "Cut ties or move out of the marital bedroom (or even the house)". She will want me to present a "united front" to the kids that we "both agree that we can't work things out" and that it will be "better for everyone if we separate" or some such tripe... Which is NOT true. MY position right now is that we COULD try to work things out if not for the overlay of the OM she is seeing. We were actually making progress before they rekindled things. We have NEVER given "us" and "our prospects" the full and fair consideration they should be given, so I am NOT ready to say "we both agree we can't." So... What DO i say? I can "leave it up to her" what to tell the kids, of course, but... they are CERTAIN, at almost 17 and 18 years, to ask me. Consensus seems to be that I do not "Out" their mom re: the Affair. Do I just say "Your Mom and I are having some difficult times in our relationship and don't agree on how to resolve them.. I offered her some ideas to resolve them (or offered to go to counseling-- should I(?)) but she does not want to work on the marriage right now." Any other thoughts on how I should respond to her inevitable pleas/requests to cover up for her with the kids and as to how I should actually respond to the kids!

Thanks all! This is all very helpful!!!