Bob Thomas recounts the story behind this belt in his book Marlon: Portrait Of The Rebel As An Artist. Apparently, James Caan and Robert Duvall had introduced Brando to the practice of "mooning" during the filming of The Godfather. One day, the trio were travelling in separate taxis in Manhattan and Duvall urged James Caan to "moon" Brando in the other taxi. Brando thought this stunt hilarious and proceeded to practice this himself on a regular basis. After Brando performed a "moon" before the assembled crowd during filming of the wedding scene in The Godfather, Caan and Duvall presented Brando with this belt.