I wouldn't schedule a MC appt. just for the purpose of doing that. If you were ALREADY MCing (and I think that MCing is a waste of time and money when one of the spouses is in an active affair), then yes, I would stand up in session, at the first time of your wife lying about the infidelity, and I would say something like "If we cannot at least be honest with each other in here, then I am clearly wasting my time. I've decided that I'll no longer waste my valuable time, nor my family's money, if my wife won't be truthful about her affair."
