Natalie Portman defends her scene with Mila Kunis in "Black Swan"

"Portman, who has previously shied away from overtly sexual roles and even turned down parts due to scripted nudity, says she has become more open in recent years to baring more than just her soul on film.
"I was figuring out my own sexual identity, likes and dislikes and all that stuff, and it's weird to be doing stuff on film as you're figuring it out," she says.
The actress, who is known for choosing tasteful-but-complex roles, says that she has no moral objections to being nude on screen, although she fears the potential for exploitation.
Mila Kunis, Natalie Portman and Darren Aronofsky at Variety's LA Series Screening of Black Swan in Hollywood - November 15 2010

"It's annoying, because online bulls**t interferes with what I want to do artistically. I'm not opposed to sexuality or nudity in a film, but I'm very opposed to pornography sites and you're pretty much giving them material if you do any of that. It's always a big dilemma for me."
Mila KunisMila Kunis attending the AFI FEST 2010 "Black Swan" premiere

The actress defends her scene with Kunis and builds hype for the film in one fell swoop, telling V of the performance, "It's not raunchy -- it's extreme." Source: www.popeater.com