The two were working on the promo all last week — and have been spending a lot of time together off the set in Los Angeles. A source told me: "Things just didn't work out between Justin and Cameron. "They decided to part ways — but they didn't tell anyone. He's got a tour coming up this year and wanted to concentrate on that, but it seems he's really hit it off with Scarlett while working on the video."
On Wednesday, 2nd January, Scarlett was at the after-party for the premiere of Justin's new movie, Alpha Dog, at Social Hollywood in LA. Our source said: "She walked in keeping her head down. When she met Justin they looked very close and chatted away for ages.
"There were other people trying to speak to Justin but he kept his attention on her for around an hour. They looked very intimate. But he's still trying to make it look low key—because he left with his mum Lynn later through a back exit."
Justin, 25, was still with Cameron when he asked Scarlett to play the leading lady in the vid believed to be based on his relationship with Britney Spears.
Scarlett has always liked Justin. They've always had a flirtation - that's why Cameron was threatened by her." With good reason. The decision to cast the 20-year-old as the video vixen pushed Timberlake's relationship with Diaz to the breaking point, and paved the way for Johansson to move in for the kill. "She could not believe he went behind her back to put her in the video," says a Timberlake pal. "Cameron was very jealous of Scarlett." Adds the source, "they definitely got together after she did the video."