So she gives up on our M, has an A, and I have to pay her for it. Wonderful.
Welcome to Family Law, American Style, at least in about 35-40 states for the man. I know -- it sucks. Adultery is a tortious act (breaking of a contract) and ought to be actionable as such, in my opinion. Yet not only is it NOT, in these "no-fault" world of ours, but -- like you said -- many times the cheater ends up getting COMPENSATED for their cheating.