A pregnant woman went to the gynecologist, and when asked that was the problem, she responded, "Well, whenever I take off my clothes, my nipples get hard."
Shocked, the doctor took a deep breath, then asked, "Your nipples get hard?"
"Yes" quite innocently came her reply.
"Undress so I can check" replied the still amazed doc.
So, she undressed, and he got down to the feeling and massaging, trying to reach an answer.
After some considerable time, the doctor, still looked puzzled, said, "Well madame, I don't know what you have, but it sure as hell is contagious!"