The former "That 70s Show "starlet plays opposite Portman in the Darren Aronofsky-directed thriller "Black Swan" about the cutthroat ballet world -- but she remained mum on some of the steamy details of the plotline, according to an interview with BlackBook.
"It's like a real-life version of the third act of 'Swan Lake,'" Kunis told the magazine. "I just feel like such a d----- because I can't talk about it. It's not even that big of a deal. It's a f---ing movie. It's not like I'm saving the world."
She hesitated about dishing too much on the rumored sex scene with Portman but confessed she understood the appeal of a scene in which they steam up the silver screen.
"Sure," she said. "It's two girls making out , and guys have a thing for that. And Nat is like every guy's dream. She's a nerd's idea of heaven.
"The whole thing is silly, but I can see why people care."