Natalie Portman's haunting performance in "Black Swan" takes a sensual turn as she rehearses for her role as the Black Swan, en pointe and enraptured. Her intense gaze meets the camera, and with a flick of her tongue, she moistens her lips, hinting at the forbidden pleasures that lie beneath her prima ballerina's tutu. Mila Kunis, as her rival and lover, watches with envy and desire, her own body yearning to be touched, to be the center of attention on this stage of carnal hunger.