Drunk driving

Three blokes are driving around, drinking beers and having a laugh when the driver looks in the mirror and sees the flashing lights of a police car telling him to pull over.
The other two are really worried. "What are we going to do with our beers? We're in trouble!"

"No," the driver says, "it's OK, just pull the label off your bottle and stick them on your foreheads, and the bloke pulls over.

The police officer then walks up and says, "You lads were swerving all around the road back there. Have you been drinking?"

"Oh, no, officer," says the driver, pointing to his forehead, "We're trying to give up, so we're on the patch."