Peter Sarsgaard recently revealed how 'bizarre' it was doing a sex scene for Very Good Girls with Dakota Fanning having Naomi Foner, Maggie Gyllenhaal's mom, as the director.

In an interview with E! News, when asked how it was filming the scene with his mother-in-law, Sarsgaard said, "Bizarre, totally bizarre... I hadn't read [the script] that carefully, so I didn't realize I was going to be doing a sex scene- that was the real surprise."

The 42-year-old actor missed the "sex scene" part in the script because he did the movie out of Foner's will.

"My mother-in-law's asking me to be in a movie that she's directing," Sarsgaard added. "I didn't have the same scrutiny about the project that I would have with something else."

When it came time to film the scene, both Foner and the 19-year-old actress didn't have experience with filming a racy scene.

"I basically told them, I know how to do this," Sarsgaard explained. "I said [to Dakota], 'You're going to lay down and I'm going to disappear out of frame and you're going to make a face and I'm not going to be there while you're pretending I'm having sex with you."

Very Good Girls, also starring Demi Moore, premiered at the Sundance Film Festival in January. The movie is about two Brooklyn girls (Fanning and Elizabeth Olsen) who make a pact to lose their virginity the summer after their freshman year of high school. Both end up falling in love with same street artist and drama pursues.

"What I wanted more than anything was it to be a fly on the wall experience," Foner told Entertainment Weekly. "I wanted nothing more than for women of all ages to walk into it and to feel 'Oh, yeah I remember that'...And have a model for themselves of some sort."

The Blue Jasmine actor and wife Maggie Gyllenhaal have been married since May 2009. The couple have two daughters together, Ramona,6, and Gloria Ray,1.