Walking the Brick
A police man on duty saw a man with a brick on a leash. Being the man that he was he went over and said, "Nice dog you've got there."
The man replied, "It's not a dog, it's a brick, dummy!"
The policeman said "I'm really sorry for wasting your time" feeling embarrassed and strolled away quickly.
When the policeman was out of sight the man bent down and whispered to the brick: "Got him there didn't we Rover?"