A man is lying in a hospital bed wearing an oxygen mask over his mouth. "Nurse," he mumbles. "Are my testicles black?"
Nurse raises his gown, holds his penis in one hand, and his testicles in the other... She takes a close look and says "There's nothing wrong with them sir."
Man pulls off oxygen mask, smiles at her, and says very slowly... "Thanks for that, it was lovely, but listen very carefully. Are- my- test- results- back?"