In an interview with People Magazine back in 2020, Clooney shared that the twins have taken a liking to the classic gross-out prank described as the Nutella-in-the-nappy joke.
"They both have learned to play pranks, which is good fun. I did work with them on putting Nutella in a diaper and then eating it," he explained. "Whenever a stranger is around, they'll come in holding it, like, 'Papa, it's a dirty nappy!' and I go, 'Okay, I'll take care of it,' and then they eat the Nutella out of the nappy."
George laughed about the inevitable "freak-outs" as a result of this prank, and said proudly at the time. "Yeah, I taught them that."
The Clooneys tied the knot in 2014 after meeting the previous year, the pair later welcomed their twins in 2017.