Serial prankster CLOONEY punks pal Matt DAMON!

NationalEnquirer.com

 MATT DAMON knows darn well his old pal GEORGE CLOONEY’s a serial practical joker, but George still got him darn good while filming their new flick, “The Monuments Men,” starring Matt, JOHN GOODMAN, BILL MURRAY and George – who also wrote and directed the true story of art historians sent behind Nazi lines during World War II to recover some of the world’s greatest works of art.

Said a source: “George got his idea for pranking Matt because he was so damn serious about working out every morning before shooting started. Bill and John kept teasing him, but Matt cracked that he’d be laughing when they didn’t have stamina for the tough hiking scenes ahead. That’s all George had to hear! He had the prop guys prepping packs for the hike fill Matt’s with solid metal bricks, weighing about 50 pounds. The other guys’ packs had lightweight padding, but George told them to pretend they felt super-heavy.”

When the guys strapped on the packs, Matt groused: “What the hell’s in here, rocks?!”

By day’s end, he was sweating profusely, complaining his back and shoulders hurt. “The guys kept telling him they felt just fine – even though they don’t work out,” said the source.

“After the scenes were shot, Matt dropped his pack, opened it – and everyone burst out laughing when the metal bricks tumbled out; then went hysterical when George, John and Bill displayed the plastic bubble-wrap that had filled their packs.

"Matt just kept yelling that payback’s a bitch and George had better watch out!"