Stop in for a cup of coffee

A duck walks into a bar and asks for a beer.

The bartender says “Sorry, we don’t serve beer to ducks.”

The duck goes out and comes back again and asks for a beer.

The bartender says “I already told you we don't serve beer to ducks”

The duck leaves and comes back a couple minutes later and asks again for a beer.

The bartender says “Look, if you come back and ask for a beer again, I’m going to nail your feet to the bar and use you as a hat rack.

The duck goes out and comes back in again and asks “Do you have any nails?”

The bartender says “No!”

The duck says “Great! Can I have a beer?”