The Up in the Air star tells Playboy magazine she's had two vivid encounters about the mystery man, and still can't understand why he crept into her "dream brain".

She says, "I dream about someone I find really creepy but other people might find totally attractive. I've had two sex dreams about him, which is really awkward. I woke up like, 'What the hell was that about?'"

Anna also candidly opens up about one sex encounter, during which she picked the wrong soundtrack and N.E.R.D.'s Lapdance played as she and her partner were getting in the mood for love.

"It was just too on the nose, and we ended up laughing," she giggles. "It's a really sexy song... We were both trying to stay in the moment."