George Clooney talks twins, Matt Damon's 'dad bod' in new film

— -- Becoming a father has taught George Clooney a valuable skill: He can now "can change a diaper like a pro," he said.

Clooney, who welcomed twins in June with his wife, Amal Clooney, spoke to ABC News' Michael Strahan about becoming a first-time father.

"One wakes the other one up," George Clooney said.

The actor shared a milestone in his children's' lives, saying, "Three days ago, we started them on a little thing called solid food."

"I've been diaper man. I'm like, 'No problem,'" he said. "Then yesterday morning was a wakeup call ... Wow, it was crazy."

George Clooney was joined for the interview by his longtime friend Matt Damon, whom he directed in the new film "Suburbicon."

Damon, no stranger to fatherhood himself as the father of four daughters, said that he was looking forward to celebrating Halloween this year with his family, saying, "My wife makes me dress up with the kids."

"It's anything that makes them happy, really. But, no, we get into Halloween. We like it," Damon added.

"We dressed up Stella as a strawberry," Damon added of his youngest daughter.

George Clooney called dressing up young children "cruel."

"If you dress up your kids when they're 4-and-a-half months old, then you're just doing that for ... you," he said.

"Suburbicon" is set in a peaceful suburban town in the late 1950s and follows Damon's character as he falls into violent crime following the murder of his wife.

In order to star in the film, Damon told Strahan that he had to get a "dad bod."

"It was funny 'cause he had ... not long before done, like, a 'Bourne' movie. And I'd seen, like, pictures of him. And he was cut and, like, built and ripped," George Clooney said. "I was like, 'Jeez, I hope he doesn't show up like that.'"

"And he walked in like the Pillsbury Doughboy. And I was like, 'There we go,'" Clooney added.

Damon said that during filming of the movie, "I was over 200 pounds, which is big for me."

George Clooney said that "every time I looked over [on set], he's ... pounding Doritos." Damon said that was just him "working."

"I had so much fun," Damon added of making the film, which he called one of his "darkest" yet. "I've never been able to do something like this in a movie."

George Clooney said that he wants to film to be "entertaining and fun and dark."

"I always think that you can never solve problems in films," George Clooney added. "You're always going to be behind the eight ball a little bit. Because it takes you two years to make a movie. So if you're trying to do something topical and general ... you're going to be out of date by the time that movie comes out."

"We don't want this to be, 'Eat your spinach,'" he added.

"Suburbicon" hits theaters nationwide on Oct. 27.