Article continues below advertisementGeorge 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.Article continues below advertisementSource: MEGAGeorge Clooney lost on a role in 'Thelma & Louse.' Article continues below advertisementClooney, who rose to fame as Dr.