A father and his son go into the grocery store and see the condom aisle. The son asks his father why there are so many different boxes of condoms.

The father replies, "Well, you see that three-pack? That's for when you're in high school. You have two for Friday night and one for Saturday night."

The son then asks his father, "Well what's the six-pack for?"

The father replies, "Well, that's for when you're in college. You have two for Friday night, two for Saturday night, and two for Sunday morning."

Then the son asks his father what the 12-pack is for. The father replies, "Well, that's for when you're married. You have one for January, one for February, one for March..."