"It was in the sex scene between husband and wife that things started to go bad. ... It was the hardest scene, very difficult," she said. "I respect him so much and he respects me so much. I know his wife, he knew my husband and introduced me to my boyfriend. It was very awkward. Like brother and sister having to do a sex scene."
"The Take," directed by Brad Furman, opens Friday in New York and Los Angeles.
Perez plays Marina de la Pena, the wife of an armored-truck driver (Leguizamo) who struggles with rehabilitation and tracking down his assailant after a shooting.
"We have a great marriage in the beginning of the movie and I'm kind of a regular neighborhood wife. We go to church every Sunday, we enjoy our simple nice life, I'm a simple nice woman in love with her husband and children," said Perez, who was nominated for an Oscar for her supporting role in 1993's "Fearless."
Perez and Leguizamo, 43, managed to get through the scene by talking about their own experiences and about relationships in general.
"It took a lot to go there and be honest," she said. "He has a wonderful marriage, but even in a successful marriage you have times when things are not good and sometimes that plays in the bedroom. And we went for it."
Even though the experience was "shocking" for her, Perez said that "in the end, it was one of the best intimate scenes I've done."