Justin Timberlake and Cameron Diaz reunite!

Exes Justin Timberlake and Cameron Diaz reunited Friday night at the Whiskey Bar in the Sunset Marquis Hotel in West Hollywood reports People Magazine.

The ex-couple - who started dating in 2003 - are believed to have split
following a huge row over their plans for the Christmas period.

In January, Justin Timberlake and Cameron Diaz had a very public bust up at a Golden Globes party. Now a patron tells PEOPLE that Timberlake had joined director Martin Scorsese and about eight other people at a table inside the hotel's bar.

Then, at about 1 a.m., Diaz arrived. "Cameron never joined their table," says the observer. "She just showed up and Justin got up and started talking to her. They were being very discreet.

"They weren't kissing or holding hands or anything, but they were being very friendly," the observer adds.

In other news, Cameron Diaz was spotted getting cozy with Blood Diamond Oscar nominee Djimon Hounsou at L.A.'s Hyde Lounge on Thursday.

"It looked like the perfect post-Valentine's Day date," a patron tells PEOPLE of the pair, who were with several other friends.

"They were totally vibing each other, lip-on-lip action," says the source. "Cameron looked so happy... Djimon followed her every move."

Diaz, 34, and Hounsou, 42, hit the dancefloor for Michael Jackson's "Burn This Disco Out" and Gnarls Barkley's version of "Gone Daddy Gone," says the onlooker, adding, "They were dancing really close, bodies pressed together."