In a clip from the upcoming career retrospective "Hugh Grant: A Life on Screen" shared by Variety, the British heartthrob admitted he was not looking forward to shaking his tail feather in the holiday classic.
"I thought, 'That's going to be excruciating, and it has the power to be the most excruciating scene ever committed to celluloid,'" the 59-year-old said. "He hated the dance scene -- Hugh's the least musical person in the world," added director Richard Curtis.
Instead, Grant's Prime Minister cutting a rug through 10 Downing Street to "Jump" by The Pointer Sisters became one of the most beloved parts of the 2003 romantic comedy.
"It did delight everybody, and I think it's the highlight of the film for a lot of people," Hugh's "Love Actually" co-star Colin Firth said in the clip. But at the time, Grant maintained his anxiety for the moment "action" would be called on that particular scene.
"I certainly dreaded filming it, and Richard kept saying... 'Don't you think we better rehearse the dancing scene?'" Grant recalled. "And I'd say, 'Oh yeah, yeah, actually I've just, I've gotta rehearse some lines, you know, my ankle hurts today.'"
"And then on the day -- I mean, imagine, you know, you're a grumpy 40-year-old Englishman. It's 7 o'clock in the morning. You're stone-cold sober and it's, 'OK, Hugh, if you'd like to freak out now.' It was absolute hell," Grant explained.
"I do remember him making a terrible fuss about the dance," Firth co-signed.
"Hugh Grant: A Life on Screen" airs December 23 in the U.K.