It's begun already - Robert Pattinson is being linked to new leading lady Emile de Ravin and shooting hasn't even started yet!

Rob's Twilight saga co-star Kristen Stewart is rumoured to have chosen her Edward over long-term boyfriend Michael Angarano shortly before he relocated to New York to film Remember Me alongside the newly-single former Lost actress.

And according to Star magazine, Kristen - who is currently rehearsing for upcoming The Runaways in L.A. - is feeling "nervous."

“Kristen’s been calling him nonstop since he’s been in New York and gets uneasy when he doesn’t answer,” says their source.

“She’s nervous he’ll fall for Emilie. She thinks it’s only a matter of time before he hooks up with another girl.”

The source adds: “Rob could be Emile’s rebound guy. He’s her type, boyish, with chiseled features.”

Mmm, we didn't have Kristen pegged as the jealous type – still, if Kristen is dating Rob, we wouldn't blame her for wanting to keep hold of her man.

Rob & Kristen's awards tease