I got a great Polish joke

A guy walks into a bar, orders a beer and says to the bartender, "Hey, I got this great Polish Joke.

.." The barkeep glares at him and says in a warning tone of voice: "Before you go telling that joke you better know that I'm Polish, both bouncers are Polish and so are most of my customers" "Okay" says the customer,"I'll tell it very slowly."