The Dentist's Sexual Encounter

[The Joker]

A man picks up a girl in a party. They proceed to her place and
things are starting to heat up. He takes his shirt off and washes
his hands. He takes his pants off and washes hands again.

So the girl tells him: "I bet you're a dentist."

Surprised he says: "that's correct, how did you know?"

"You washed your hands a few times, so I figured you're used to
it." They go on and they have sex.

Then she says: "you know what? I'm willing to bet you're a very
good dentist."

"How can you tell?" he asks.

"I didn't feel a thing..."