One of the things you learn on this fogged-out rollercoaster ride is how much you have to STAY ON MESSAGE. It's like a political campaign -- you have to keep things short, simple, on-message, and repeat them often. No, you don't let outright lies go unchallenged, but you don't dwell on them, either.
Lots of similarities.
Anyway, I had to tell my wife two or three DOZEN times, things like "No, your affair is not the only issue we have. It is, however, our immediate OBSTACLE. End your affair, come back to the marriage, and I think you'll find me more than willing to discuss and work on any and all issues, including mine."
and
"I fully understand that there were problems that we had that led to these conditions. And I will take my full 50% responsibility for them. But I will not, and DO not, take any responsibility for your reckless and selfish decision to have an affair. End your affair, and we can work on ALL of our marital issues, together."