You must be laugh.....‏

A Policeman was patrolling late at night off the main road.

At nearly midnight, he sees a couple in a car, in lovers' lane, with the interior light brightly glowing.

He carefully approaches the car to get a closer look. Then he sees a young man behind the wheel, reading a computer magazine. 

He immediately notices a young woman in the rear seat, filing her fingernails.

Puzzled by this surprising situation, the constable walks round the car and gently raps on the driver's window. 

The young man lowers his window. 'Uh, yes'?

The cop asks: 'What are you doing'?

The young man says: 'Well, constable, I'm reading a magazine'.

Pointing towards the young woman in the back seat the policeman says: ' And her, what is she doing'?

The young man shrugs: 'Sir, I believe she's filing her fingernails'.

Now, the policeman is totally confused. 

A young couple, alone, in a car, at night in a lover's lane ... And nothing obscene is happening!

The constable asks: 'What's your age, young man'?

The young man says: 'I'm 19, sir'.

The constable asks: ' And her, ..... what's her age'

The young man looks at his watch and replies: 'She'll be 18 in 11 minutes.