There’s a dark side to Hollywood’s iconic sex and nude scenes.

A new documentary called “Body Parts” that premiered Sunday at the Tribeca Film Festival exposes the frightening and vulnerable position actresses have been put in for decades on sets run by powerful male directors.

Steamy sex scenes, they insist, are anything but sexy.

Rosanna Arquette recalled that her first nude shoot, in the 1981 comedy “S.O.B.,” was never meant to happen. When she took the role, the actress said, the intimate moment was not mentioned in her contract.

Then the cameras rolled.

“Let’s just lose the bikini top,” Arquette, 62, remembers famed director Blake Edwards, whose wife Julie Andrews also went topless in the movie, telling her surrounded by crew and fellow actors, such as William Holden and Robert Preston. She added: “I was 19 at the time.”

Rose McGowan said that it was completely normal for filmmakers to even hold day-long bikini casting calls.

“They would write a role for a girl in a bikini for no apparent reason,” the actress, 48, said, adding that it was a pervy excuse for the creative team to get together and watch a parade of scantily clad women.

Jane Fonda remembered that she first personally dealt with on-screen nudity when she moved to more permissive France in the 1960s. 

There she met director Roger Vadim, who directed 1960’s “Blood and Roses” and was previously married to Brigitte Bardot and partnered with Catherine Deneuve. Vadim and Fonda wedded in 1965 and three years later, he cast her in “Barbarella,” a sexually charged film about an astronaut. Lines of trust were crossed, she said, even for a husband and wife.

“Roger promised me that he would use the letters in the titles to cover the important things,” Fonda, 84, said of the risque opening credit sequence in which she strips. “Which was only partly [true].”

As the actress floats in midair, viewers can clearly see her breasts. “I was 30 — I should’ve known better,” she added. The pair divorced in 1973.

Another little-known fact about Tinseltown’s titillating moments is that body doubles often stand in for a star’s naked persona. One double says in the movie that “America would be shocked” by how often audiences are not actually seeing the celeb’s actual skin.

Another double is still in a lather over history’s most famous shower scene.

Marli Renfro, 84, played a clothes-less Marion Crane (otherwise performed by Janet Leigh) in Alfred Hitchcock’s “Psycho” in 1960.

“That’s the back of my head, my hands, my arms, my belly button,” she fumed in the doc. “Janet Leigh wrote her autobiography and let on that she did the whole thing. Pissed me off!”

Some decades later, two actresses mention their disturbing time with James Franco in the film. In 2018, Franco was accused by five women of being sexually inappropriate with students in his acting classes, including Sarah Tither-Kaplan.

In “Body Parts,” directed by Kristy Guevara-Flanagan, Tither-Kaplan said that back in 2017 she was “so grateful” to be cast from class in the indie film “The Long Home,” until the production went south.

“Thing started to get tricky because scenes were being added that weren’t in the script,” she said of previously unannounced sexually explicit sections. Another actress was let go for not participating, and Tither-Kaplan knew if she complained she’d “lose her job.”

In a 2021 interview with SiriusXM, Franco said “I did sleep with students” and claimed he suffered from “sex addiction.”

Actress Emily Meade starred in Franco’s show “The Deuce” as a prostitute-turned-porn star who frequently appeared in sex scenes. And while Meade, 33, doesn’t specifically call out Franco, her discomfort on set led to the first “intimacy coordinator” — a sex scene choreographer and go-between for the actors, writers and directors — on a network show.

The role was much-needed on the series. “I was having to constantly dislocate to show up at my job,” she said.  

The landscape in Hollywood is changing thanks to the MeToo movement, many of the interview subjects say, but McGowan has a harsher take: “The Hollywood machine is something to be survived.”