The girl has been watching him and opines: "You must be a dentist". The guy, surprised, asks "Yes.. how did you figure that out?" "Easy..." she replies "you keep washing your hands".
One thing leads to another and they make love. After it's over the girl tells him: "You must be a GOOD dentist".
The guy, now with an inflated ego, answers: "Sure, I'm a good dentist. How did you figure that out?" The girl replies "I didn't feel a thing!"
