A father and his son go into the grocery store and come upon the comdom 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 are in highschool. You have 2 for Friday night and 1 for Saturday night."
The son then asks his father, "What's the 6-pack for?" The father replies: "Well that's for when you are in college. You have 2 for Friday night, 2 for Saturday night and 2 for Sunday morning." The son asks his father what the 12-pack was for. The father replies: "Well, that's for when you are married. You have one for January, one for February, one for March, one for.......