Jennifer Garner on Ben Affleck's "Gone Girl" nude scene

"Gone Girl" is now a box office hit, and Jennifer Garner knows it's not just the film's whodunit mystery that has people buying tickets.

Appearing on "The Ellen DeGeneres Show," Garner spoke about her husband's full frontal nude scene in the big-screen version of Gillian Flynn's novel.

When DeGeneres noted Affleck's manhood might have contributed to the film opening at No. 1 over the weekend, Garner replied, "I think you're probably on to something."

"What I have to say is, 'You're welcome,'" she joked. "I just try to consider myself a charitable person and I wanted to give back. You give me so much, I wanted to give something back to all of you."

According to Garner, she and her husband didn't talk about the full-frontal scene beforehand. "It wasn't a discussion. It was like 'Hey, you know, at work today Fincher talked me into coming out of the shower,'" she said, doing an impression of Affleck. "And I was like, 'Oh, cool, well, I hope he had on a wide lens.'"

Garner was appearing to promote her new film, "Men, Women and Children," which is now in limited release and opens wide on Oct. 17.