In the nearly four years they've been together, Justin Timberlake and Cameron Diaz have been dogged in equal measure by bust-up and engagement rumors. Now, thanks to Star, the split chatter has taken an early lead in 2007.

The tabloid is convinced the paparazzi-loathing pair has decided to part ways (and somewhere, Britney Spears does a panty-free happy dance), citing their separate Christmas vacations as evidence of an estrangement.

Video: Justin and Cameron split?

Justin, 25, reportedly decided to head home to Tennessee to celebrate the birth of the baby Jesus with his family, while Cameron, 34, hit the slopes in Vail, Colo., with her clan.

"They had been planning to be together in Tennessee with his folks," a mole tattles to the tab. "But he came out alone and she stayed in L.A."

Star claims the "SexyBack" singer was the one who pulled the plug on the relationship, and quotes him as telling pals he was partying with at a local club, "Me and Cameron? We're done."

Justin also supposedly spent some time in Tennessee getting re-acquainted with long-ago squeeze Veronica Finn, a real estate agent who was once part of the girl group Innosense (sic), which was managed by Timberlake's mom and briefly counted Britney as a member.

"Veronica is around all the time," a source tells E!'s Marc Malkin. "Cameron gets crazy jealous."

Finn, however, tells E! that while she and Timberlake "have been good friends for a really long time," they were never alone together over the holidays and she hung out with his entire family.

As for whispers that he's now flying solo, Finn maintains, "That's news to me about Justin and Cameron breaking up."

Both stars remain mum on these latest rift rumblings, although Diaz was a no-show at Wednesday's Los Angeles premiere of Timberlake's tattoo-crammed flick, "Alpha Dog."

She also wasn't by his side when he chatted up Kate Hudson at her New Year's Eve bash, a tête-à-tête that quickly sparked romance babbling (Kate's rep, however, insists they're just friends).

The longtime lovebirds were last spotted together in New York back in mid-December, when Cam introduced Justin during his well-received "Saturday Night Live" hosting gig, which featured his insta-classic performance of "D**k in a Box." They later hit the show's afterparty hand-in-hand.

Of course, in recent months they've been vocal about their aversion to settling down, with Diaz declaring herself a "commitment-phobe" to Ellen DeGeneres and telling reporters at a press event for her oddly underperforming romantic comedy "The Holiday," "I don't even want a dog. I don't. My cat just died, and I don't want a cat."

Timberlake was equally emphatic about avoiding the ties that bind, responding to DeGeneres' questions about engagement rumors and teasing over whether she should get a bridesmaid dress by quipping, "Know what? Go ahead and reserve one. The only thing is, you'll have to stay the same size for the next 15 years."

Still, there's been talk that the two made a really big commitment a few months back, plunking down nearly $17 million to buy a 12-bedroom house in Hawaii, their favorite surfing spot. Justin, however, was quick to put the kibosh on claims they'd said "I do" to beachfront property.