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 Fred, and he 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, but, in a few moments, she was able to regain her composure.
'I am so sorry,' she said. '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.
She ran out of the room.