A 78 year-old man came into the Doctor's office and complained of
 being tired.  The Doctor asked if he'd done anything unusual lately.

    The man said, "Well, Wednesday night I picked up a 20 year old 
 secretary, went back to her place, and nailed her 3 times. Thursday, 
 I met a 19 year old waitress at the diner and we went out to Lover's
 Rock and made love 4 times.  Friday, I went out with an 18 year old
 friend of my granddaughter's and we ended up making it in the back of
 my Ford.  Saturday I was lured into a motel by 17 year old twins..."

    The Doctor said, "That's absolutely astonishing.  But with all the
 dangers of sex these days, I hope you took proper precautions..."

    "Of course," the old geezer replied, "I game 'em all phony
 names..."