Ham on Wry

HERE'S A STUMPER for you riddle-a-holics: A man went to visit a relative who was drying out in a detox ward. When he arrived at the door, the nurse explained she could only admit him if he were a relative of the patient. The indignant visitor replied that indeed he was and he'd tell her just how. He explained: "Brothers and sisters I have none, but that man's father is my father's son."