Elvis Presley's Pee-Stained Underwear

A pair of pee-stained underwear worn by Elvis Presley in 1977 went on the auction block in 2012.  Apparently Elvis wore this underwear under a jump suit during a concert and he pissed his pants during the concert.  This pair of underwear was on display at the Elvis-A-Rama museum in Nevada.  I wonder how big the urine stains were on Mr. Belding's underwear???