In the psychological thriller Black Swan, actress Mila Kunis plays Lily, a new dancer at the New York City ballet company, who catches the eye of the artistic director. This is immediately threatening to Nina (Natalie Portman) because she has been waiting for years to take her place as the company’s star ballerina, only to constantly be worried that Lily is looking to replace her. As their twisted friendship turns into an intense rivalry, Nina becomes engulfed in the dark side that she finds so sensuous and appealing in Lily.

At a press conference to promote the film, Mila Kunis talked about how excruciating ballet is as a sport, working with a filmmaker like Darren Aronofsky and being in an industry herself where she’s seen her peers give in to their desire for perfection. Check out what she had to say after the jump:

Before reading, if you haven't watched the trailer for Black Swan, click here.

Question: Since this is a different type of role for you, what was the casting process like?

MILA KUNIS: I don’t know how or why I got hired. I never really asked. I didn’t want him to second-guess himself. I just went with it and said, “All right, if you trust me, I’m game.” That’s all it was. It was an amazing opportunity, which I don’t regret and never want to question. I thank Darren every day for it.

Have you ever seen “Swan Lake” on stage?

KUNIS: I did not get the opportunity to see a full version of “Swan Lake” until about a year ago. Every time that I went to see ballet, it was always a fragment of it, so I was never able to see it in its full length.

How did you appear so effortless and sensual, when you were not a ballet dancer prior to this?

KUNIS: It was far from effortless or sensual. It was three months of training beforehand. I was not a ballet dancer. You can only fake so much physicality, so you have to immerse yourself in this world, in the way that somebody walks, talks and handles themselves. So, it was three months of training, seven days a week, four or five hours a day, before production started, and then during production it was pretty much exactly the same.

What surprised you most about ballet?

KUNIS: The thing about ballet that I never knew about is that it’s one of the most excruciating sports that I’ve ever been a part of. I say sports because they train constantly, every single day. Your body changes. Your shoulders drop, your chest opens up and there’s a certain posture that I don’t naturally have because I slouch. So, for three months, I had to constantly stand up straight. And he way that they hold their arms, because they’re always moving their fingers while they’re dancing, also changes the way that they talk in real life. And the feet are different because of the ballet shoes. There are a lot of little things.

In playing this role, did you always have to keep it in the back of your mind, when your character was actually there and when she was just a delusion?

KUNIS: Whenever Natalie and I were in the same scene, I’m pretty sure we did it about every which way possible. However she would do it, I would do it the opposite. The truth of the matter is, as much as we worked on the script and as much rehearsal as we did, you didn’t even know how it was going to be played. It was all so finicky that you just tried to give as much as you could in every single take, and every single take was completely different. There was nothing continuous.

What was your experience working with Darren Aronofsky?

KUNIS: Working with Darren was truly one of the most amazing experiences of my life. He’s a brilliant director. It’s a rarity when you come across somebody that you trust so much, where you can just immerse yourself in a role and feel like there’s a safety net underneath you, in case you fall. I always looked at Darren as a safety net, and he was absolutely great.

Can you talk about doing the same sex love scene in this film? Was that your first?

KUNIS: I did a film, called After Sex, with Zoe Saldana, where she played my girlfriend, but we never had a sex scene. We had the scene of what occurs after you have sex, so maybe that doesn’t count. So, this would be my first.

Did you and Natalie have any discussions, prior to doing your love scene, to make things more comfortable?

KUNIS: Anytime you do any intimate scene on film, it’s going to be a little uncomfortable, whether it’s the same sex or the opposite sex. The great thing about this is that Natalie and I were actually lucky enough to be friends prior to production, which made it all a lot easier. We didn’t really discuss it very much. We just kind of did it. It made sense for the character. It wasn’t put in for shock value. It wasn’t something that we needed to justify in our heads, as to why we were doing it. That was it. The truth of the matter is that we were friends before we started the film, so that made it a lot easier.

Doing something like that, do you ever worry about being exploited by the filmmaker?

KUNIS: I trusted Darren. Doing something like this with Darren was very safe and as comfortable as something like this could be. Personally, I never had a fear of being exploited.

Have you ever done a role where you just wanted to be perfect?

KUNIS: I feel like every role you take, there’s a part of you that obviously feels like you can do it. I don’t know if perfect is the right word because I don’t believe in perfection. I don’t think it exists. But, I think that striving to do something well is in every single part. The physicality of this was probably the hardest of anything that I’ve ever done. When it comes to characters, whether it’s comedy, drama, horror or romance, it’s all the same. You want to be honest with a character and play it truthfully, and you want to be genuine with your character. The physicality aspect of it was as close as I’ve ever come to just a complete mental breakdown.

Have you seen the quest for perfection take its toll on some of your peers, either artistically or physically?

KUNIS: Yeah, both. Sadly, in any industry and in any work-related environment, females always strive to achieve a certain amount of perfection, whether that be skinny or pretty. It’s a constant, in our society. It’s probably elevated a little bit, in the industry that I’m in, because everything is a matter of opinion. I can think someone is pretty, but the person next to me can think that they’re unattractive, so people strive to achieve a certain form of perfection constantly, but it’s impossible because it’s an opinion. So, yeah, I’ve had a lot of friends that have been affected by that.

How relieved were you when this film was over, so that you could just go pig out on food?

KUNIS: Oh, my god! You have no idea! It took me five months to lose 20 pounds, and it took me hours to gain it back. It was magical, how quickly it all happened. Before production ended, the last time I had to do any sort of dancing, I ran home that night and had a massive bowl of mac and cheese. I was so excited. Going back to my poor eating habits, after having really good eating habits, my stomach was a little unsettled, but after production ended, the first thing I did was go and get Panda Express at the airport terminal, at Virgin America at JFK, and I was so excited. And then, I landed in L.A., got in my car, drove to In-N-Out and had a double-double, animal style with a root beer float, and it was fantastic. That is what I did. It was so good.

What was your reaction when you saw the film, for the first time?

KUNIS: I’ve seen it a couple times. The first time I saw it, it was very, very, very rough and I was like, “Oh, that’s the movie we made.” And then, the final cut that I saw, I was blown away by it. I was there and I remembered most of it, but I had no idea how Darren was shooting it. The camera really is a part of the movie. You truly forget that there’s a camera there because it is a whole other character, so I was blown away by it and I was there. I was like, “This is pretty amazing!”

Do you consider yourself more a black swan or a white swan?

KUNIS: I think I’m a little bit of both. I think everyone has a little black swan in them, it’s just a matter of when you let it out. But, I would say I have a healthy balance of both, I would hope. I’m not nearly as adventurous as a black swan, but at times I would like to be.

What do you think about all of the Oscar talk for this film and your performance?

KUNIS: It all makes me very uncomfortable. As long as people respond to the film, I’m not even going to touch upon awards because I can’t. I don’t know. I have no idea what to say to that type of question. I think it’s an honor and I think it’s great. If people like it, then I couldn’t be any happier. Anything else is just all very new to me.