A man and his son enter a shop, and the son asks his dad what condoms are. His dad dutifully explains. His son then asks why there are three in a pack. The dad explains that they are for older school boys: One for Friday, one for Saturday, and one for Sunday. His son asks why some packs have six in. The dad explains that they are for college boys: Two for Friday, two for Saturday, and two for Sunday. His son's eyes widen as he spots the pack of twelve, and he asks who they are for. The dad explains that they are for married men: One for January, one for February...