The Condom Display

Standing near the check out stand at a local drug store,
a boy spotted a display of condoms.
"Hey Dad, what's a three-pack for?" asked the boy. "Those are for the weekend.
Two for Friday night, and one for Saturday," replied the father.

"Then Dad, what's a six-pack for?" asked the son.
"That's when she moves in with you.
Two for Friday night, two for Saturday, and two for Sunday."

"Then Dad, what's a twelve-pack for?"
"That's for when you're married. One for January, one for February, one for ... "