«زَانِي مَا يْآمِنْ عَلَى مْرَاتُهْ»

In this traditional, husband-centered moral judgment, a man who betrays his marriage gives up any real peace of mind about his own wife. His conduct sets the household's tone, and by showing her that vows can be broken, he is seen as weakening the restraint that might otherwise keep her faithful.

More broadly, the proverb warns that wrongdoing tends to come back home. Someone who disregards a moral boundary should not expect those closest to him to keep it, since his own example quietly invites them to follow the same path.

Suited to moral commentary on a man who cheats yet expects loyalty at home, or more broadly on how a person's misconduct sets a pattern others may follow. Because it implies a serious accusation, use it about types or situations rather than naming individuals.