Guy goes into a high-end wine and cigar bar and tells the barkeep to give him a snifter of Louis XIV brandy. He sniffs it, rolls it on his tongue, and yells at the bartender, "This is not Louis XIV brandy--it's Louis XIII brandy! Get me what I asked for!"

While the barkeep's busy looking, a guy at the end of the bar decides to have some fun. He drains his brandy, brings the snifter under the bar, and pisses in the snifter. Then he approaches the "expert":

"Sir, I'm very impressed with your knowledge--you're a real connosseur. I wonder if you can help me identify this brandy?"

The hotshot looks doubtfully at the other guy's snifter, sniffs it, rolls it on his tongue, then spits it out. "This tastes like piss!!" he shouts.

"It is," says the other guy, "but whose is it?"