A cop sees a car weaving so he pulls it over. He walks up and sees it's a blonde behind the wheel. When he bends down, he smells booze on her breath.
He says, "I'm going to give you a Breathalyzer test to see if you're under the influence of alcohol."
She blows up the balloon, then he walks it back to the police car.
He comes back to her car and says, "It looks like you've had a couple of stiff ones."
She says, "You mean it shows that, too?"