As a comedian I early kinda learned to "love" trying to outperform the other comedians backstage by telling the sickest things I could imagine.

Now I don't know how known this joke is for people "outside" of the comedy business since I've only heard it backstage and don't know if anyone ever have told it on stage.

However there's a documentary about this joke but I don't know if anyone have seen it :P

So have you heard about the joke?
Have you heard abut the aristocrats?
What do you think about it?

If you don't know but want to know you can find the documentary or maybe just check Wikipedia. There's also a website called "The Aristocrats Joke Database" with a collection of the joke.