We always imagine what it would be like to fake a sex scene, and many actors have been candid about how awkward they can be.
And then there's Nicole Kidman, who likes her co-stars to have the freedom to be as rough as possible.
"I want him to feel free. Actors have to protect each other in a way. The idea of humiliating another actor or being humiliated myself is devastating," the 48-year-old said in an interview conducted by director Lee Daniels for Interview magazine's October issue.
In a Lee-directed film "The Paperboy," Nicole's character fell in love with John Cusack's character, who was an inmate awaiting execution.
After he was released, the pair shared an intimate moment together in the kitchen of their home.
According to Nicole, the scene would not have been successful without letting John have the freedom to insert his character's dominance.
"I said, 'John, you're hurting her.' You were bent over the washer and dryer," Lee recalled. "I said, 'Nicole, are you okay?' And you said, 'I'm fine.' But it was clear that he was throwing you around the f****** room like a mop," he remembered. "And the next day you came to set bruised."
"That's why, if he's a little rougher than he knows he's being, the last thing I want to say is, 'Oh my gosh, you hurt me.' Most actors are like that. We all go, 'No, no. I'm fine. Don't worry about it.'"
She continued, "If you're tentative and scared that you're hurting someone or that you're overstepping a line or that there's a boundary that you've crossed, it makes everybody too cautious."
Nicole also reflected on how her divorce from Tom Cruise in 2001 influenced her role in "The Hours," the film for which she won an Academy Award.
"Your own emotional state comes into play," she said. "I was going through an enormous amount of turmoil. And even though it was appropriate at times for the character at other times it wasn't. But I would just bleed it in; it would manifest in different ways."
Nicole married Keith Urban in 2006.