A guy walks into a bar and orders a beer. He only brought enough money
for one beer though. As he's drinking his beer, which was quite
expensive, he realizes how bad he has to go to the bathroom. Not wanting
anyone to drink his expensive beer, he takes out a card and writes on
it, "I spit in this beer", and walks to the bathroom.
When he comes back about 15 minutes later, there's another card next to his beer saying, "I spit in it too."
