Adultery refers to marital inFidelity. When two partners, of whom at least one is married to another party, have sexual relations - even transient ones - they commit adultery. Christ condemns even adultery of mere Desire. 170 The sixth Commandment and the New Testament forbid adultery absolutely. 171 The Prophets denounce the gravity of adultery; they see it as an Image of the Sin of idolatry. 172