Charlize Theron's Awkward Sex Scenes

Actress Charlize Theron (search) says it's always uncomfortable shooting love scenes, even if you're acting with your boyfriend.

Theron and Stuart Townsend (search) are a couple off-screen, and have an on-screen romance in the new film "Head in the Clouds," (search) set in the 1930s and '40s, which opens in some cities this weekend.

Theron, who spoke to reporters before she was injured on the set of "Aeon Flux," said there were some comforts shooting the scene with her real-life beau, Townsend.

"You're not getting naked in front of a stranger" she said, according to AP Radio.

Still, she said the scene may be awkward for her friends to watch, because they know the two as a couple in real-life.

"No matter how well you play the character, it's still odd for them, I'm sure," she said.

In the film, Theron romps topless in the bath with Townsend, dresses up in S&M leather and dances an erotically charged tango with on-screen lover Penelope Cruz.

Yes, Charlize, who won an Oscar for her turn as splotchy-faced,serial killer, Aileen Wuornos, is no "Monster" anymore. 

In her current wartime romance, the South African beauty plays a bohemian photographer who embraces the hedonistic spirit of 1930s Paris, sharing a bed with Townsend's school teacher and Cruz's Spanish stripper.

The film features a passionate, lip-biting kiss with Cruz, a daring, up-against-the-wall oral sex scene with Townsend and an abundance of naked couplings.

But it's that steamy bath scene -- in which the 29-year-old Theron appears naked but for a fedora and tie -- that's really going to shock audiences.

"That scene is rather nice because when the audience first sees her, they think it will be discreetly filmed because the frame line is just above her chest," said director John Duigan.

"But just at the right moment, Charlize rises up out of the water -- so it delivers, quite unselfconsciously, what the audience is hoping for.

"The tie was her idea."

Theron, who dropped 25 pounds in the month between wrapping "Monster" and starting "Clouds," initially balked at the sex scenes with Townsend, whom she's been dating since 2000.

"People say it's impossible to have [on-screen] chemistry with somebody you're in a relationship with, but in this film, it's really about destroying the relationship."

Duigan says the real-life lovers were obviously very comfortable together and brought "a genuine erotic charge" to their love scenes.

"That chemistry is very important because these are two characters who come from very different worlds and they're drawn to one another by a powerful passion," he said.

"That sense of passion needs to be -- and is -- palpable in the film."

Theron and Cruz -- who have both trained as dancers -- were equally at ease with their sexy tango scene.

"Having chosen to play these roles, they played them to the hilt -- no compromise," Duigan said.

The Associated Press and the New York Post's Megan Lehmann contributed to this report.