Never be seen naked

The young bride's mother had some old-fashioned ideas of marriage, and passed them on to her daughter.

"Never let your husband see you in the nude" she advised. "You should always wear something".

"Yes, mother" replied the obedient girl.

Two weeks after the wedding, the girl and her brand-new husband were preparing to retire when the guy asked "Dear, has there ever been any insanity in your family?"

"Not that I know of" she answered. "Why?"

"Well, we've been married for two weeks now and every night

Spoiler:

you've worn that silly hat to bed".