George Clooney says he lost his "masculinity" on the set of The Descendants.

Famed for being one of Hollywood's most eligible bachelors, the star explained he was worried about his image after being filmed running in flip flops.

Shot in Hawaii, the actor is shown in action in the flimsy footwear which resulted in a funny stance.

"I don't run great in flip-flops. It was a little frustrating because I did it the first time in those shoes and I thought it would be funny and I was sort of screwing around. Then [director] Alexander [Payne] seemed to like it and I realised I would have to do it a lot more," George told US website E! Online.

"And I also realised it would sort of end all masculinity for me for the rest of my life!"

The 50-year-old also admitted to being the most immature cast member on set.

Despite starring alongside much younger actors who portrayed his on-screen family, George has revealed that he was told off by them for messing around.

"There's really only one kid actor [in the film], Amara [Miller]," Clooney said.

"Shailene [Woodley] was the adult on set. I've got the fart machine and she was like, 'Really? Put that away, we gotta work.'"