A Great Dentist

A guy and a girl met at a bar. They got along so well that they decided to go back to the girl's place. A few drinks later, the guy took off his shirt and washed his hands. He then took off his pants and washed his hands.
   The girl watched him and said, "You must be a dentist." 
   Surprised, the guy said, "Yes, how did you figure that out?"
   The girl said, "Easy. You keep washing your hands."

One thing led to another and they made love. Afterward, the girl said, "You must be a great dentist."
   Now with an inflated ego, the guy goes, "Yes, I sure am. How did you figure that out?"

"Easy," the girl replied, "I didn't feel a thing."