A father and his son go into the drug store when they happen upon the condom aisle. The son asks his father why there are so many different boxes of condoms.

The father replies, "Well, you see that 3 pack? That's for when you're in high school. You have 2 for Friday night and 1 for Saturday night."

Nodding agreement, the son asks his father, "Then what's the 6 pack for?"

"That's for when you're in college," the father says. "You have 2 for Friday night, 2 for Saturday night, and 2 for Sunday morning."

Following this line of logic, the son enthusiastically asks what the 12 pack is for.

"That's for when you're married, son. You have one for January, one for February, one for March..."