"Round for the house" joke

A drunk walks into a bar and says loudly, "Bartender? A ROUND FOR THE HOUSE, and have one yourself, too!"
The crowd cheers, the bartender pours and passes out the drinks, then knocks back a shot himself.
"That'll be $80 for the round," says the bartender, to which the man replies, "I don't have a plug nickel."
The angry bartender drags the man to the door and roughly throws him into the street.
The next night, the drunk again walks in and says, "Bartender? A ROUND FOR THE HOUSE-and go ahead and have one yourself, too!"
As the crowd cheers, the bartender reasons to himself that no one would come in and do that twice, and that the man probably has the money for the previous night, so he passes out the shots and knocks one back himself.
"Ok, that's $80 for last night, and $63 for tonight,"
The man replies, "I don't have a pot to piss in or a window to throw it out of, sorry to say."
The bartender, enraged at this, smashes the man in the head over and over as he drags him to the door and again throws him roughly into the street.
The next night, amazingly, the bartender hears over his shoulder as he's working, "Bartender? A ROUND FOR THE HOUSE."
Turning around, he can't believe the drunk is back for a third time.
"What, nothing for me this time?"
"Hell no," says the drunk. "You get MEAN when you drink!"