EXCLUSIVE: George Clooney Reveals Which Baby Names Amal Has Already Shot Down

The first-time father-to-be told ET what he is 'not allowed to do' when it comes to the names of his future children.

George Clooney is failing the baby name game -- at least, according to his wife, Amal.

While promoting the trailer for his latest directorial project, Suburbicon, at CinemaCon in Las Vegas on Tuesday, the 55-year-old actor chatted with ET's Kevin Frazier about the impending arrival of his twins, expected in June.

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"I don't know how you fully digest [having two], but I'm excited," the first-time father-to-be told ET. "It will be fun."

Clooney joked that he considered naming the children after his thriving tequila company, Casamigos, but the idea was quickly vetoed by Amal. "My wife says I can't name them Casa and Amigos. That's the one thing I'm not allowed to do," he said.

The Oscar winner added, "It was just a thought. I mean, you know, it's a family business."

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The Suburbicon director was also joined by Julianne Moore, who stars alongside Matt Damon in the crime comedy. Moore, 56, is confident that Clooney will be a "natural" when it comes to fatherhood.

"He'll have a great time. He'll be a natural father," the actress admitted to ET. "He was great with the little kid on our set. He was really, really wonderful."

Moore added that the Money Monster star was "awesome" to work with, continuing, "He's a great director and sets an amazing tone on set. It was a joy to come to work everyday, and everybody said so."

For more on the actor's upcoming bundles of joy, watch the video below.