The Onliest Joke Ever Told

Knock Knock
Who’s there?
Yo mama.
Yo mama who?
Yo blonde redneck mama who crossed the road to walk into a bar and screw in a lightbulb – you know your fat, dumb, drunk, crooked-politician lawyer mama, who pleasures 12 inch pianists.


Source: http://www.free-funny-jokes.com