Night Patrol

A night patrol policeman and saw a parked car, illuminated by the inner light. He approached the car and saw a couple quietly installed.
A young man sitting in the vehicle steering wheel, flips a computer magazine while a young woman sitting in the back seat, knitting.
Curious to this strange situation, the official comes and knocks on the window. The young man down the window.

• What are you doing there ? - Asks the puzzled policeman.
• Well, I read a magazine!
  And pointing to the young woman, the policeman asks:
• And she, what is she doing?
  The young man shrugs:
• I think she is knitting a sweater.
  The officer is totally confused. A young couple alone in a car at night and nothing happens immoral!
  The policeman asks:
• How old are you, young man?
• I'm 22, sir.
• And she, how old is she?
  The young man looks at his watch and said:
• She turns 18 in 20 minutes.