In other words, don't sabotage the session before finding out whether W is actually receptive to MC. So, a lot of validation, STFU and letting the MC lead. Lay out the olive branch that says hey, I'm here willing to do the work.
Maybe I'm mistaken, but I haven't seen the issue as a "are you willing to do MC, wife?" but rather one of "Will MCing with my wife be effective while she is having an affair?"
Many wayward spouses are WILLING to do MC. It's just that usually it's either to validate their waywardness, prove to hostile friends and family that "see? I tried" or -- in the worst cases -- to get "permission" from a counselor to help them move toward divorce.
