He tells her to take her pants, she does, and he starts rubbing her thighs.
"Do you know what I am doing?" asks the doctor?
"Yes, checking for abnormalities." she replies.
He tells her to take off her shirt and bra, she takes them off. The doctor begins rubbing her breasts and asks, "Do you know what I am doing now?", she replies, "Yes, checking for cancer."
Finally, he tells her to take off her panties, lays her on the table, gets on top of her and starts having sex with her. He says to her, "Do you know what I am doing now?"
She replies, "Yes, getting herpies - thats why I am here!"