Robert Pattinson and Kristen Stewart
At the premiere of "New Moon". REUTERS

The Cannes Film Festival debut of On the Road, based on the Jack Kerouac novel of the same name, offered fans an opportunity to see Kristen Stewart with two of her favorite men.

Fans lined Cannes' iconic Promenade de la Croisette on Wednesday for a glimpse of the star who plays Marylou in the relatively low-budget film, which was produced by Francis Ford Coppola. (Stewart signed on before her lead role in Twilight catapulted her to superstardom.)

To the delight of fans, Stewart's boyfriend (and Twilight costar) Robert Pattinson surprised the crowd when he showed up at the screening to support Stewart. The famously private couple was even seen getting cozy on the roof of the Casino Barriere after the film.

Pattinson's attendance left many wondering if K-Stew would extend him the same courtesy at the premiere of his film Cosmopolis. It turned out she did reciprocate, but -- shockingly -- she arrived with her On the Road co-star Tom Sturridge. The British actor is a close friend of Pattinson and is expecting a child with girlfriend Sienna Miller. Stewart, who wore a figure-hugging red gown, leaned on Sturridge and held his hand tightly. The actress arrived about 15 minutes before Pattinson and quickly made her way to the Palace of Festivals.

Directed by David Cronenberg, Cosmopolis is a dark metaphor for the economic crisis. Pattinson stars as Eric Packer, a 28-year-old billionaire who enjoys limo sex and being careless with guns. Packer travels through a traffic-filled Manhattan seeking what he regards as self-liberation.

Both Cosmopolis and On the Road are up for the prestigious Palme d'Or prize, which is awarded to the director of the best feature film of the official competition.