From PEOPLE Magazine Click to enlarge
GIRLS PILE UP BEHIND BARRICADES by the thousands for the chance to gaze into his brooding green eyes—and on more than one occasion, Robert Pattinson has denied requests to sink his teeth into their necks. But for the first two months of Twilight's production, the brooding English actor was desperately failing to attract the one girl whose attention he most craved: Kristen Stewart. "I thought to myself, because she's so serious, I've got to be really serious," the actor recalls. "I felt like an idiot just following her around saying, 'You really should read some Zola, and there's this amazing Truffaut movie.' " Stewart was not impressed, he says. "She started calling me on things. 'Have you actually watched this movie? Yeah? What's it about?' "

Anyone who hasn't been sleeping in a coffin knows by now that Stewart eventually came around. As her three-year relationship with actor Michael Angarano cooled off this spring, the 19-year-old actress started stealthily going on dates with her 23-year-old costar, meeting up at concert venues and Los Angeles' most secluded hotels. That confirmed what many people involved in Twilight believed was inevitable: The two quirky actors who portray the vampire Edward Cullen and his hopelessly devoted, mortal girlfriend Bella Swan have ignited a red-hot romance offscreen.

Director-turned-matchmaker Catherine Hardwicke says that Pattinson and Stewart had sparks flying between them from the first "Action!" During the audition process, "I had the top four finalists for Edward, and they all came over and did scenes with Kristen. I was looking to see who really had that magic, who had that chemistry," Hardwicke recalls. "Rob and Kristen had it from the first day." Everyone noticed the connection instantly—especially Pattinson himself. "When I read Twilight, and there are these moony descriptions of Edward as a godlike figure, I thought there was no way I could play him," he recalls. "But when I got in the room with Kristen, there was a certain chemistry. She's basically the reason I did the movie." Hardwicke told G2 last year that Stewart had experienced a similarly strong magnetism toward Pattinson after their screen test and insisted to Hardwicke, "It has to be Rob."

It took Pattinson a year of flirtatious advances—including a series of marriage proposals (that's just his schtick, he maintains)—to win Stewart's affection. While she was going strong with her then-beau Angarano, Pattinson had a fling with costar Nikki Reed, which insiders say broke off in part because Pattinson couldn't keep his eyes off Stewart. Over pizza on location in Montepulciano, Italy, and during cast poker nights at costar Peter Facinelli's home in L.A. and countless nights out in Vancouver while filming New Moon, their attraction inevitably intensified, and, despite concerns about mixing love and work, they finally succumbed to their feelings. "They're genuine, and they're very talented," explains costar Ashley Greene of the common ground they share. "It's like a secret potion that you can't really pinpoint, but they both have it."

They're also both self-proclaimed loners who bonded over a passion for music and an aversion to the Hollywood scene. Labeling herself the ultimate homebody, Stewart noted that her friendship with Nikki Reed works because "we both play guitar, and we can sit on a porch for, like, a week straight and be entirely content." Likewise, Pattinson, who is adept at guitar, piano and harmonica, describes himself as low-maintenance. "When I was young, I wanted to play the piano in a bar, to be the old dude with a whiskey glass, all disheveled," he has said. "I'm a bit of a loner. I'm boring. I stay home, watch TV and eat a lot of fast food."

Pattinson's lonely nights eating in front of the television are over for now. While shooting New Moon in Vancouver, he and Stewart have been spotted shopping for vintage T-shirts together by day and cozying up at Kings of Leon and Bobby Long concerts by night. The couple also go out with the pack, sitting together at cast dinners and their favorite local bars. The cast is fiercely protective of Pattinson and Stewart's privacy, and the couple go to great lengths to keep their relationship shielded from direct sunlight.

But some things you can't keep hidden no matter how hard you try. Just ask Catherine Hardwicke. While filming Twilight, one romantic scene between Pattinson and Stewart told her everything she needed to know. "When they were kissing," she recalls with a smile, "Rob got a little passionate and fell off the bed!"

THEY'RE STARTING TO LOOK ALIKE!

The Twilight lovebirds prove that they are a perfect match both onscreen and off

SHADES

PLAID SHIRTS

HOODIES

MANNERISMS

KNIT HATS