Proof once again that there are no new jokes. And for further proof, may I contribute:

A lady of the evening walked into a bar with a duck on a leash. The bartender says, "Hey! What are you doin', comin' in here with that pig?"
The hooker says, "It's not a pig, stupid, it's a duck."
To which the bartender replies, "I was talkin' to the duck."