Nurses aren't supposed to laugh…

 "Of course I won't laugh, I'm a professional nurse. In over twenty years I've never laughed at a patient."

"Okay then," Fred said and proceeded to drop his trousers, revealing the tiniest man thingy the nurse had ever seen. Length and width, it couldn't have been bigger than a AAA battery.

Unable to control herself, the nurse started giggling then almost fell to the floor laughing.

 "I'm so sorry," said the nurse. "I don't know what came over me. On my honor as a nurse and a lady, I promise it won't happen again.

 Now tell me, what seems to be the problem?"

 "It's swollen," Fred replied.

Things went downhill from there.