Darren Aronofsky recalled unsuccessfully trying to start a feud between Natalie Portman and Mila Kunis to ramp up the onscreen tension in 'Black Swan': 'They're both very clever and were instantly privy.

Natalie Portman and Mila Kunis reflect on how Darren Aronofsky tried and failed to push a rivalry between the two stars on the set of 'Black Swan'

Speaking with Vogue in a new interview to mark the 2010 film's 15th anniversary, the actress — who was joined by costar Natalie Portman and director Darren Aronofsky — shared how she transformed herself to portray a professional ballerina on-screen.