Are my testicles black?

A man is lying in bed in a Catholic hospital with an oxygen mask over his mouth. A young auxiliary nurse appears to sponge his face and hands.
“Nurse,” he mumbles from behind the mask, “Are my testicles black?”
Embarrassed the young nurse replies, “I don’t know, I’m only here to wash your face and hands.”
He struggles again to ask, “Nurse, Are my testicles black?”
Again the nurse replies, “I can’t tell. I’m only here to wash your face and hands.”
The ward sister was passing and saw the man getting a little distraught so marched over to inquire what was wrong.
“Sister,” he mumbled, “Are my testicles black?”
Being a nurse of longstanding, the sister was undaunted. She whipped back the bedclothes, pulled down his pajama trousers, moved his penis out of the way, had a right good look, pulled up the pyjamas, replaced the bedclothes and announced, “Nothing wrong with them!!!”
At this the man pulled off his oxygen mask and asked again, “Are my test results back???”