'It's not a big deal': Kristen Stewart brushes off topless scenes in new film On the Road

'So not a big (deal)': Kristen Stewart, who plays Marylou in On the Road, said it was 'so no big [deal]' to go topless in a car scene with costars Garrett Hedlund and Sam Riley

Not only does the Twilight star strip down for the role of a 16-year-old bride, she simulates a certain sexual act with the two men with her hands in the car.

Racy: The 22-year-old starlet was only 17-years-old when she accepted the role

But the star says the racy scenes came quite naturally.

Stewart told MTV News at the Toronto International Film Festival: 'It didn't bother me.'

The entire cast reportedly underwent a three-week 'beatnik boot camp' for the film, led by Kerouac biographer Gerald Nicosia, in which they read literature pertaining to the Beat Generation.

She added: 'You can do no wrong with [director Walter Salles]. He puts so much inside of you. In the four-week rehearsal process, it was okay to ask any question, to bring up any story, to really over-analyze everything and intellectualize everything.'

Stewart continued: 'Once we got on set, it was so about just breathing and letting it happen. He put so much trust in us, so it was like, "Okay, so I have to take my clothes off?" It's so not a big [deal].'

The Adventureland actress was only 17-years-old when she accepted the role, but thanks to delays she got a chance to mature a bit first.

'I should have definitely been older than 17 while playing this part, absolutely,' she said.

'[My performance] would have been done very differently if I was younger. I wouldn't have played the part, obviously.'

The story is based on the years Kerouac spent traveling the United States in the 1940s with his friend Neal Cassady and several other figures who would go on to fame in their own right, including William S. Burroughs and Allen Ginsberg.

Getting handsy: Not only does the Twilight star strip down for the role of a 16-year-old bride, she simulates a
certain sexual act with the two men with her hands in the car

The film, scheduled for release of December 22, boasts an outstanding ensemble including Amy Adams, Viggo Mortensen, Kirsten Dunst, Steve Buscemi, Terrence Howard and Elisabeth Moss.

While many feared that Stewart's affair with married director Rupert Sanders last July could spell the end of her career, Stewart has seemed to brush those concerns aside as well.

Moving on: Many feared that her affair with married director Rupert Sanders last July could spell the end of Stewart's career

After a six-week absence from the public, the Runaways star emerged last week to promote On the Road at the Toronto Film Festival and a New York screening at Disney Park Avenue.

While posing with Hedlund and Salles, Kristen looked fierce in her black ALC trousers, androgynous and unbuttoned white Balenciaga shirt, and Jimmy Choo heels.

Stewart will next be seen in The Twilight Saga: Breaking Dawn – Part 2, set for release November 16.

Lainey Gossip reported that she is already back together with her costar and ex-boyfriend Robert Pattinson, 'But they [Robert and Kirsten] are worried about how it might affect his career, like whether or not there will be some kind of crazy backlash,' according to the website.

Hitting the road: While posing with Hedlund and director Walter Salles, Kristen looked fierce in her black ALC trousers and an androgynous, unbuttoned white Balenciaga shirt

Newlyweds: The film, coming out December 22, has an outstanding ensemble including Amy Adams, Viggo Mortensen, Kirsten Dunst, Steve Buscemi, Terrence Howard, and Elisabeth Moss