George Clooney is known as one of Hollywood's hottest playboys, but despite the long list of A-list women he has dated, some fans still speculate the actor may be gay.

But that is not the case, according to Clooney's sister Adelia Zeidler, who recently gave her first ever interview to The New York Daily News.

Clooney, 51, has never married any of his celebrity lovers, except for a short union to actress Talia Balsam that ended in 1993. But Zeidler, 52, laughed off any notion that Clooney's reluctance to wed has anything to do with him being gay.

"That's quite ridiculous, we don't even listen when people say things like that anymore. I think he decided that in his life he could have the career or he could have a family," she said. "And so when he decided to go full bore into the acting. That was where his focus was going to be."

CLICK HERE to check out photos of George Clooney's sister, Adelia Zeidler.

Clooney's current relationship with Stacy Keibler has fueled speculation that the pair may get hitched, but Zeidler said she thinks a wedding with Keibler or anyone else is unlikely.

"No, I would say he probably will not get married," Clooney's sister said. "If I had to guess I would have to say no. I know everyone says, 'Well, Warren Beatty said he'd never get married and then he met Annette Bening,' but you know, that's the only example people can think of, so it doesn't bode too well."

Zeidler said Clooney realizes that he can't be fully committed as both an actor and a husband, so he understands his limitations and lives his personal life accordingly.

"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 wife and the home and all of that," she said. "And in the business that he is in he has to be able to get up and go. The majority of actors don't really make their marriages work."