George Clooney's twins may only be 12 weeks old, but they've already got their own distinct personalities!
The 56-year-old star sat down with ET's Carly Steel while promoting his new film, Suburbicon, at the Venice Film Festival on Friday, where he revealed that Alexander and Ella actually couldn't be more different.
"We figured these kids are going to be looked at a lot and watched and [have their] every move sort of judged, and we wanted them to at least have a break with the names," he reasoned. "So we looked for some sort of normal names. We didn't have any great inspiration. It wasn't Alexander the Great and Ella Fitzgerald."
"Alexander Hamilton?" Damon inquired.
"It was Alexander Hamilton," Clooney jokingly confirmed.
And while Clooney had been preparing for fatherhood since finding out Amal was pregant last fall, he admitted that the idea that he would be a dad didn't really sink in until they were born in June.
"I suppose [the realest moment is] just the minute they came out," he said of fatherhood. "None of it is real until all of a sudden they're standing there covered in slime and crying. You're like, wait a minute, what is that? We were just two and now we're four."
"Everything changes pretty quickly," he added.
Suburbicon hits theaters on Oct. 27. See more on the Clooney twins in the video below.