Emma Watson used to ruin Harry Potter takes as a child actress by mouthing the lines of her co-stars.
The star of the new remake of Beauty and the Beast relived the "traumatic" experience with US late night TV host Jimmy Kimmel, who found it all very funny.
Watson lamented being "such a loser" as an out-take from an early Harry Potter film played.
"You laugh but this is actually quite traumatic for me because I created issues because of this," Watson said.
"I would ruin takes! First [the directors] would be like, 'Cut! Emma, you're doing it again. You're mouthing Dan's lines.' And I'd be like, 'Ooh! I'm so sorry! So sorry! Oh, I feel so bad!'
"I couldn't help myself, it was like, I was such a loser. I really loved those books, I really wanted to do my job well, and I kind of overdid it."
Beauty and the Beast opens in New Zealand cinemas later this month.