A guy goes to a super market and goes to aisle 12 and asks for a box of condoms.
The lady asks, "what size?"
The guy says "I don't know."
So the lady asks him to pull down his pants. She tugs a few times and says "You need a box of large condoms."
A guy behind him decides to asks for a box of condoms, too. So the lady asks again, "What size?"
The guy replies, "I don't know." So the lady asks him to pull down his pants and tugs a few time and says, "Get a box of medium condoms."
A teenager in aisle 11 sees the lady in action and decides he wants in. So he goes to aisle 12 and asks "Can I have a box of condoms?"
The lady asks again, "What size?"
The teenager answers, "I don't know."
So the lady asks him to pull down his pants. When he does, she tugs a few times, stands up and announces, "Clean up in aisle 12."