Free drinks for everyone
One night, a drunk comes stumbling into a bar and says to the bartender: "Drinks for all on me including you, bartender." So the bartender follows the mans orders and says: "That will be $36.50 please." The drunk says he has no money so the bartender slaps him around and throws him out.
The next night the same drunk comes in again and orders a drink for everyone in the bar including the bartender. Again the bartender follows instructions and again the drunk says he has no money. So the bartender slaps him around and throws him out.
On the third night he comes in, the drunk orders drinks for all except the bartender. "What, no drink for me?" replies the bartender. "Oh, no. You get violent when you drink."