Chris Weitz Left The Make Out Scene to Rob and Kristen

MTV How exactly does a person direct two of the biggest movie stars in the world during a make-out scene? How do you approach the task if one's playing a vampire and the other is still in her teens? For Robert Pattinson and Kristen Stewart's "New Moon" lip-lock, director Chris Weitz just sat back and shut up.

"Capturing those [scenes] is really a question of just allowing the actors to do their work," Weitz told MTV News in a recent interview. "They know their characters. They know the tone they're supposed to hit."

The director's job in this case, Weitz explained, is not to intrude on the connection the actors have already established — especially considering RPattz and KStew had gone through a cinematic romance in 2008's "Twilight."

"It's not like when they're about to kiss, I'm leaning in and saying, just off camera, 'Tender, tender!' or anything like that," he laughed. "I just let them do their thing. I think it would be creepy and inappropriate for me to advise them how to kiss one another or what it's like to be young in love. I'm 40 years old. I'm not going to Polanski out on them."

One area Weitz did take an active role in was making sure the "New Moon" set was free of any Pattinson and Stewart relationship rumors. "I very much want the set to be completely free of all those concerns and any pressures that are coming from the outside world — paparazzi — and the tremendous attention that they're under," he said.