A cop sees a car weaving all over the road and pulls it over. He walks up to the car and sees a nice-looking woman is driving and smells liquor on her breath. He says, "I'm going to have to give you the breathalyzer test to determine if you are under the influence of alcohol."

She blows up the balloon and he walks over to the police car.

After a couple of minutes comes back and says, "It looks like you've had a couple of stiff ones."

She replies "You mean it shows that, too?"