For three decades, she and her husband “dined out” on the gag, but a British doctor who sits in the House of Lords has confessed to making up a condition called “cello scrotum.” The fictitious ailment, which for 34 years has worried male players of the large string instrument, was something Elaine Murphy and her husband John invented as a prank in 1974 after reading about a similar chafing condition called “guitar nipple.” The baroness came clean this week in a letter to the current issue of the British Medical Journal, noting that a researcher in a previous article had referenced the condition as if it were real.