A man picks a woman up in a bar and takes her home.
When he takes off his shoes and socks, it is apparent that his toes have had something dreadful happen to them.
"Eeek!" she says.
"Oh, I used to have toe-lio," he says.
"You mean polio?"
"No, toe-lio."
So they continue. When he takes off his pants, his knees look like they have been beaten with sledge hammers.
"Eeek!" she says.
"Oh, I used to have the knee-sles," he says.
"You mean measles?"
"No, knee-sles."
Still undaunted, they continue.
When he takes off his underpants, she laughs and says, "Don't tell me! Small-cocks!"