Credit: Mark Seliger

Whatever the status between Robert Pattinson and Kristen Stewart, the New Moon costars have high praise -- and good-natured mockery -- for one another in a new cover interview for Harper's Bazaar.

Stewart asserts earlier claims that Pattinson is severely unathletic. "Rob can barely jump rope," she tells the magazine. It's even inspired a nickname! "I call him Flippy because when he does his stunt rehearsals, he flips around," she says, imitating a penguin's walk. "And God, when he tries to run..."

Pattinson banters back and accuses her of Googling herself more than he does. "She just looks at herself," he says. "I look up my competition more than she does. I'm incredibly shallow."

And who's the more romantic of the two? "I'd have to say Rob is," Stewart says. "I think romance is anything honest. As long as it's honest, it's so disarming." She calls his singing "heartbreaking."

Stewart, Pattinson says, is "a unique girl. You really don't meet many people like Kristen."

And it appears that the twosome hang out -- to say the least -- even when they're not fulfilling press obligations. reported exclusively that the pair spent the night together at Hollywood's Chateau Marmont on Oct. 29.

The next morning they shared breakfast from Noah's Bagels (a plain bagel with walnut cream cheese for him; a blueberry with butter for her).

Later, during a New Moon screening, "Rob wanted a cigarette so he went outside with Kristen for about 15 minutes," a source tells Us. "They were hugging, as Rob was smoking his cigarette and then he leaned down and kissed her on the lips. He had his arm around her almost the whole time."