Elvis Presley snuck into a screening of his own movie to heckle himself.
The 'Blue Suede Shoes' singer became friends with Johnny Lang during his two years of military service and the 88-year-old veteran has fond memories of his "funny as heck" pal hurling insults at the screen when they went to watch his 1958 musical 'King Creole'.
Johnny told America's Closer magazine: "People don't realise that he was funny as heck.
"Elvis yelled out, 'This guy can't act! He can't even sing! I can't believe he's on screen.'
"Somebody shouted, 'Would you mind shutting up?' Nobody knew it was him."
Johnny - who has penned a memoir called 'My Army Days with Elvis: Friendship, Football and Follies' - hit it off with the 'Jail House Rock' hitmaker on their first meeting and quickly became part of a group who spent the weekends off base at Elvis' house.
He recalled: "We'd play football every Sunday. Elvis would come out and sign autographs for fans and then we'd go play.
"I've never seen a guy who treated everybody with so much respect.
"He said, 'God gave me the talent but without these fans, I wouldn't have what I have today.' "
Elvis valued Johnny's friendship because he knew he wasn't only interested in him because of his fame.
Johnny said: "I asked him once how come we were friends. He said, 'You'd like me if I was a janitor - and thank God I'm not - but that's why you and I are friends.'
"Loyalty was a big thing for him. If you didn't have any loyalty, you weren't in the group."
Johnny visited his friend for the final time the day before he returned home, and though Elvis invited him to see him perform in Las Vegas, they never met again.
He said: "I cried like a baby when I heard he died."