A drunk staggers into a bar and says to the bartender,
"I’d like to buy everyone in the bar a drink and get one for yourself too!"

The bartender makes the drinks and everyone raises their glass and yells "CHEERS!" and downs their drinks.

The bartender says "That’ll be $37.50."

The drunk says, "I don’t have any money!"

This infuriates the bartender who then jumps over the bar and beats the living daylights out of the drunk and throws him out into the street.

The next day the same drunk walks into the same bar and says,
"I’d like to buy the whole bar a drink, and get one for yourself, too."

The bartender figures that maybe he was a little hard on the guy the day before and decides to give the guy the benefit of the doubt.

He makes the drinks and they all say, "Salute!" and down the drinks.
The bartender says,
"That’ll be $42.50."

The drunk replies by putting his thumb to his nose, wiggling his fingers, and making a loud raspberry noise followed by,
"I don’t have any money!"

This angers the bartender even more than the first time. He jumps over the bar and beats the hell out of the drunk and throws him out into the street onto his face and kicks him a few times for good measure.

The next day the same drunk walks into the same bar, but before he can say anything the bartender says,
"Let me guess, you want to buy the whole bar a drink and I should get one for myself, too, right?"

The drunk replies, "No way, you get too violent when you drink!"