Nurses aren't supposed to laugh... 
  "Of course I won't laugh," said the  nurse. "I'm a professional. In over twenty years I've never laughed at a  patient..."
"Okay then," said Bob, and he  proceeded to  drop his trousers, revealing the smallest penis the nurse had ever seen.   In length and width was almost  identical to a AAA battery.
Unable to control herself, the nurse  tried to stop a giggle, but it just came out. And then she started  laughing at the fact that she was laughing.  Feeling very bad that she had laughed at the man's penis, she composed herself as well as  she could. "I am so sorry," she said.. "I don't know what came over me.  On my honour as a nurse and a lady, I promise that won't happen again.  Now, tell me, what seems to be the  problem?"
"It's swollen," Bob  replied.
She ran out of the room.