Mila Kunis knows what you’re not supposed to say about preparing for a movie, but she’s going to say it anyway.

The actor opened up to Vogue magazine about the intense time she spent training for the Darren Aronofsky film, “Black Swan,” for a retrospective piece in honor of the 15th anniversary of the movie.

“My prep was a lot of dancing and very little eating — which I know you’re not supposed to say, but it’s the truth. I drank a lot of broth and danced for 12 hours a day,” Kunis told Vogue.

“We were only supposed to have three months of prep before filming started, but we lost some financing, so that got extended to six months while Darren tried to find money,” she added. “It sucked for Darren, but Nat and I were so happy because we had three extra months to dance.”

“The dance training for ‘Black Swan’ started a year before the film, with two hours a day,” she said at the time. “Six months later we ramped it up to five hours a day, and the last two months it was eight hours a day, because we added choreography and cross training, so I was also swimming a mile a day.”

“The discipline was good for the part — it hurt a lot; your body is in constant pain,” Portman said, as the magazine added that the actor, “like most dancers, she survived on coffee and ibuprofen, and slept five hours a night.”

While both Portman and Kunis were exerting themselves physically to the extreme, Aronofsky was also trying ― unsuccessfully ― to play mind games with the two.

“My take is that I was trying to be a sneaky director and make them argue,” the director shared with Vogue.

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“Mila and Natalie both realized very quickly what I was doing and made fun of me, so it quickly became a joke that we all understood,” he added. “They’re both very clever and were instantly privy to whatever trick I was playing.”