The cause: Trouble usually originates between the wife and her husband's mother. Why? Marriage researcher John Gottman, PhD, says it's usually because both women are competing for the attention of the husband.
The cure: Solidarity is essential to the success of a marriage, so you both must present a united front. Husband must side with his wife in any disagreement—even if she's wrong. Mom must understand that her son is a husband first, son second.