The "Ocean's Eleven" star, who is currently romancing former wrestler Stacy Keibler, has been a serial dater since 1993 after his divorce from actress Talia Balsam.
And Clooney's older sister Adelia Zeidler is convinced the 51-year-old won't walk down the aisle again, reported New York Daily News.
"I would say he probably will not get married... If he was going to get married he would want to be a husband and be somebody who would be there, who would have the time and the ability to focus on the family and the home and all of that. And in the business that he is in, he has to be able to get up and go," said Zeidler.
"The majority of actors don't really make their marriages work. If he had children, when he was with them, he would be concerned about his career and if he was working he would be concerned about the children. And he doesn't," she added.
