I believe what I said was that in their wayward (adulterous) state, they are not a friend of the marriage. And I believe that. A person in an active affair does NOT have the marriage's best interests at heart, and in fact is usually actively working with the OM/OW on its DEMISE.
It was hard for me to "love the sinner/hate the sin" and to simultaneously see my wife lovingly and also as an enemy of our marriage.