A guy and a girl meet at a bar. They get along so well that they decide to go to the girl's place. A few drinks later, the guy takes off his shirt and then washes his hands. He then takes off his pants and washes his hands.
The girl watches him and says, "You must be a dentist."
The guy, surprised, says "Yes ... how did you figure that out?"
The girl says, "Easy... you keep washing your hands." One thing led to another and they make love. After they were done, the girl says, "You must be a great dentist."
The guy, now with a boosted ego says, "Yes, I sure am a great dentist... How did you figure that out?" The girl says, "Easy... I didn't feel a thing!"