A young lady goes to the doctors.
He asks her what the problem is, and she explains that when she walks, her c**t whistles. Amazed at this, the doctor asks her to remove her clothes and show him what she means, so she strips, walks back and forth, and sure enough, with each step there is a whistling sound.

The doctor is perplexed, never having come across anything like it in his career, so explains that he will call a coleague for a second opinion, asking him to listen carefully and give his opinion of the strange sound. So they are on the phone, she walks back and forth so the other doctor can hear it.

"So, what do you think?" asks the doctor.

"Well, sounds like some c**t whistling if you ask me..."