Natalie Portman won the only Oscar of her career in 2011, following the success of her horror film, Black Swan from the previous year. The film was directed by Darren Aronofsky on a budget of around $13 million. Alongside Portman, the movie also starred That '70s Show's Mila Kunis.

That Oscar nomination was only one of five that Aronofsky and team earned that year, including in the categories Best Picture, Best Director, Best Cinematography and Best Film Editing. At the box office, Black Swan did sensationally well, as it grossed well over $300 million globally.

All these accomplishments would have been more than enough of a tonic for Portman and Kunis, who had endured an awkward episode as they filmed an intimate scene together. The pair - who are great friends in real life - had not anticipated just how weird things could get.

Put Kunis' Name Forward

According to Rotten Tomatoes, Black Swan is the story of 'Nina, a ballerina whose passion for the dance rules every facet of her life. When the company's artistic director decides to replace his prima ballerina for their opening production of Swan Lake, Nina is his first choice.'

'She has competition in newcomer Lily, however. While Nina is perfect for the role of the White Swan, Lily personifies the Black Swan. As rivalry between the two dancers transforms into a twisted friendship, Nina's dark side begins to emerge.' Portman played Nina, while Kunis portrayed her rival, Lily.

A depiction of Natalie Portman's Nina from 'Black Swan'
via: Pinterest

Now famous for her character Jane Foster in the Marvel Cinematic Universe, Portman was first approached by Aronofsky for the part of Nina in 2000. She accepted the challenge to join his cast because the role fulfilled her criteria of 'demanding more adulthood from her' and broke her from the cycle of being typecast as a 'small, cute woman.'

Once Portman was on board, she knew exactly who would be perfect for the role of Lily. She is indeed the one who put Kunis' name forward to Aronofsky. When her friend came in for her screen test, the director was sold straight away.

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Failed To Think Too Far Forward

A few months after the film premiered, Portman had an interview with MTV where she explained the enthusiasm with which she suggested Kunis for Lily. Unfortunately, she failed to think too far forward regarding the particular scenes that they would have to do together.

"It was really crazy, because Mila and I were very good friends. And when Darren asked me, 'Who do you think could do this part? Who has sort of a similar height, coloring, physique?' I was like, 'Oh, Mila, Mila, Mila!,'" she recalled. "He met her and obviously flipped over her, and she's super talented and does an amazing job in the movie... I didn't really think through the fact that I was going to have to have sex with her in the movie."

The familiarity of performing a sex scene with a very close friend meant it was bound to get awkward. On the other hand, it did provide a safety net of sorts: "I feel like it would be easier to do it with someone you didn't know," Portman explained. "But it was great to have a friend there who we could laugh and make jokes and get over it together."

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Contrasting Energies Balanced Perfectly

At the end of the day, Kunis was pleased with how their characters' contrasting energies balanced perfectly. She felt that Nina was the superior ballerina, but lacked the passion and raw drive that her Lily had. "My character is very loose," she said. "She's not as technically good as Natalie's character, but she has more passion, naturally. That's what [Nina] lacks."

Mila Kunis as Lily in 'Black Swan'
via: ZM

While the fire between the characters was fierce, the friendship between the two actors remained intact during the course of filming. Aronofsky attempted to change this dynamic as a way to stoke the passions, but he found this was a bond too strong to be broken.

"He didn't want us to be friends while we were shooting, because we're rivals in the movie," Portman said in the MTV interview. "So we both had to do this ballet training, but he would make it at different times, and then he would tell me, 'She's doing really well,' and then tell her, 'Natalie's doing so much better than you!' But we would share the information, so we were like, 'He's messing with us. This isn't real, this isn't real.'"

The pair have not collaborated on any project since, but Portman fans will be looking forward to seeing her in the MCU's Thor: Love and Thunder next year.

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