Has Robert Pattinson Fallen For Another Co-Star?

Has the on-screen romance between Robert Pattinson and his Remember Me co-star Emilie de Ravin spilled off-screen?

The actors have been seen kissing and cuddling while shooting scenes for the flick, and Rob's girlfriend Kristen Stewart is apparently not happy about it, OK magazine reports.

"[Kristen] knows screen kisses are part of Rob's job, but it doesn't make things easier, seeing sexy photos of him and Emilie in full lip-lock," a friend of Stewart's said. Hey, it doesn't make it any easier for us either - we want Rob and Kristen to be together, not Rob and Emilie!

But is that all that's really worrying Kristen?

While she's in California filming The Runaways, Rob and Emilie have been spending a lot of time together away from the set in New York. Just last week, the two were spotted in a private room at the Soho House and they've also been seen dining at Gemma, a restaurant in The Bowery Hotel.

Friends say Kristen is so concerned about losing Rob to Emilie, she's planning on flying to New York to visit Rob as soon as she can.