‘Gone Girl’: Rosamund Pike On Working With Ben Affleck, Sex Scenes With Neil Patrick Harris

Rosamund Pike plays the enigmatic Amy Dunne in the upcoming big screen adaption of “Gone Girl,” which means she had to film sexy scenes with co-stars Ben Affleck and Neil Patrick Harris.

Delving into the film’s dark storyline (based Gillian Flynn’s bestselling novel) made for some heavy moments on set – something the actress said she fought to lighten up when the cameras stopped rolling.

“[Ben and I] could have really great conversations on set and talk for hours. And then another day, we would barely speak a word. It’s funny,” Rosamund told Glamour for the October issue. “[We] would have these scenes that were very giggly and sort of romantic. And then we’d go to this very dark place. I tried to get us out of that.”

Neil, who plays Amy’s obsessed ex-boyfriend Desi in the film, could flip the switch and have the pair in stitches.

“Neil was incredible at that. We were in hysterics in the editing room,” she said. “It was very funny doing [rehearsals for our sex] scene. David [Fincher] left Neil and me alone on that set for like two hours to make sure we could do it.

“But when it’s just two of you, basically kind of f**king on a bed, it feels so inappropriate,” she added.

And the laughter kept coming when it came to relieving the tension of playing Amy.

“There were definitely moments when I felt very uneasy with how much power Amy had. And the interesting thing is, my reaction was to laugh, to get sort of uncontrollable giggle,” Rosamund told the mag. “That was the most curious part of playing her: At the point where she’s at her most powerful, it unnerved something in me.”

Off-screen, the 35-year-old actress is pregnant with her first child (and “Gone Girl” is expected to be one of the biggest thrillers of the year), prompting the mag to ask about starting a family as her fame is set to skyrocket.

“The question is really why do so many women’s careers take off just as they have children? Is it because you are risking everything in your relationship and the risk taker in you carries through into your professional life? You have less time to worry and overanalyze—maybe that’s it,” she said. “Or the huntress instinct to provide for your family is awoken. [Either way,] with children you spend so much time reexperiencing the world as a child experiences it, and that has a nourishing effect on your imagination—in my job, imagination is key.”

“Gone Girl,” which also stars Tyler Perry, Emily Ratajkowski and Casey Wilson, hits theaters on October 3.

Glamour’s October issue hits newsstands on September 16.

— Erin O’Sullivan