Grant, who stars with Kidman in the Sky Atlantic limited series The Undoing, recalled meeting the actor for the first time at a dinner in the mid-90s, where guests included Kidman’s then-husband Tom Cruise, Grant’s then-girlfriend Elizabeth Hurley and Kidman’s sister Antonia.
“What I remember most was that she was very nice, charming, but when she spoke to her sister, she spoke in a secret language,” Grant told Entertainment Weekly. “And I said, ‘Excuse me, are you speaking in a secret language?’ And they both said, ‘Yes.’”
Asked what the language sounds like, Grant replied: “It’s weird, it sort of goes ‘eggy-peggy this, eggy-peggy that,’ and they still do it ... I’ve always liked her, she’s a silly Aussie girl.”
Antonia Kidman, the younger sister of the Big Little Lies star, is a popular journalist and TV presenter in her native Australia.
In The Undoing, Grant and Kidman play a Manhattan couple who are pulled apart by speculation over the murder of a young mother at their son’s school.
Grant also told the magazine that he embraced playing such a suspicious character after tiring of “just doing a version of Hugh Grant”.
“[I was] the charming leading man, I’m quite happy to have that behind me,” he explained. “So I was trying to find a character, really. I needed to find a very specific guy to be, not just ‘dreamboat.’”
The Undoing begins on Sky Atlantic on 26 August.