George Clooney losing a pivotal early role to Brad Pitt was the spark for years of pranks played on his leading man rival, OK! can reveal.

Veteran A-lister Clooney, 64, recently admitted he failed to land the part of thieving grifter J.D. in Ridley Scott's 1991 classic Thelma & Louise - a film that launched Pitt's career while leaving Clooney simmering with envy.



Source: MEGAGeorge Clooney lost on a role in 'Thelma & Louse.

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Clooney, who rose to fame as Dr. Doug Ross on ER, recalled his audition for the role, saying: "So, I was in TV. I was making a good living, but back then actors would say, 'Well, I'm a film actor - I just happen to be doing TV.' And I got to the final test for a role in Thelma & Louise. And, motherf-----, Brad got it." He added: "I didn't watch Thelma & Louise for years, because I was annoyed. The part launched his career in film. He was doing sitcoms and c--- before, so when it was the thing that could've launched me? F---!"But Clooney said when he finally saw the film, he accepted Pitt was right for the part, yet he couldn't shake his frustration over being sidelined for the career-defining role.

He added: "Oh yeah, (Pitt) gives me s---. "But, of course, when I saw it, I was, like, 'Well, it had to be that guy.'"



Source: MEGAThe A-listers are friends.



But a source close to the actors explained the long-term fallout was years of cruel pranks pulled by Clooney on Pitt.

They said: "George has openly admitted the impact of losing the Thelma role to Brad - but what he doesn't say is that is what planted the seed for all the pranks he has pulled on Brad over the years, some of them pretty cruel. He pretends the pranks are all about fun, but really they are motivated by poking the guy who 'stole' the role he wanted." Another Hollywood insider said: "Clooney's pranks have been relentless, from on-set jokes to behind-the-scenes antics at awards shows."

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Source: MGMBrad Pitt appeared in 'Thelma & Louise.

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Clooney has even joked he has spent years working on a practical joke that will target Pitt - which is so serious it could lead to him being arrested.

He has previously admitted he stuck a bumper sticker on Pitt's car bearing a pot plant and the declaration: "F--- cops" - which resulted in his fellow A-lister being pulled over by police.

Clooney has also sent out fake letters on letters with fake Brad Pitt heading, to stars including Meryl Streep.A source close to Clooney said: "Losing the Thelma role made him sharper, more playful, and, frankly, relentless in teasing Brad. It became part of their friendship - but despite it being born of jealousy, Pitt treats it as a joke between lifelong friends."Clooney's latest role has seen him team up with comic Adam Sandler in the film Jay Kelly.

He plays a superstar actor navigating fame, while Sandler plays his loyal manager.



Source: MEGAGeorge Clooney has spent years pranking Brad Pitt.



In one interview to promote the project, Clooney reflected on the pressures of early stardom and the lessons learned from his career trajectory. "I never missed a day," he said of his ER schedule, recalling grueling 17-hour shoots, adding: "You cannot be sick."He recalled one scene with Julianna Margulies - filmed after she took a phone call about a loved one's death.

Clooney said "she put the phone down, wiped away the tears, nailed the scene and then came back and cried." He added: "You can never let them see you sweat." Clooney, married to human rights lawyer Amal Clooney and father of young twins, added fame is a mix of opportunity and loss. He said: "There are a lot of things that get taken away from you. Independence. And listen, you will never hear us complain... but it doesn't mean there aren't challenges along the way."He also credited other early career disappointments besides Thelma & Louise with shaping his career choices.

Clooney added about his disastrous turn as the caped crusader in 1997's Batman & Robin: "(It) made me realize I had to pay attention to scripts and directors. The next three films I did (were) Out of Sight with Steven Soderbergh, Three Kings with David O Russell, O Brother, Where Art Thou? with the Coen brothers."