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Robert Pattinson, who?

Kristen Stewart is locking lips with another New Moon costar -- Dakota Fanning.

"Yes, it happens in The Runaways," Fanning told Access Hollywood of the pair's other film venture together. "We were so into the scene and into the script and the characters."

Fanning, 15, said the kiss was a passionate one.

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"We're playing Joan Jett and Cherie Currie and they're best friends in the film and became really close in real life," Fanning said of their roles in the film, which will be released next year. "And that’s something that went down back in the '70s."

The former child star has said their characters' relationship "is kind of the one that Kristen and I have in real life," adding that she and Stewart, 19, bonded immensely while filming both movies back-to-back.

"We became really close," she has said. "It's like we'd known each other our whole lives. We talk all the time."