Stiff one

A policeman sees a car weaving all over the road and hits his flashing lights. He walks up to the driver's window and sees a good looking woman behind the wheel. There is a strong smell liquor on her breath.
He says, "I'm going to give you a breathalyzer test to determine if you are under the influence of alcohol."
She blows up the balloon and he walks it back to his patrol unit. After a couple of minutes, he returns to her car and says, "It looks like you've had a couple of stiff ones."
She replies, "You mean it shows that, too?"