Trouble in Paradise for Drew & Cameron?

Sunday night's Golden Globes CAA after party at the Sunset Tower Hotel was a 'who's who' of A-list stars. But for former BFFs, Drew Barrymore and Cameron Diaz, the night was anything but starry.

Diaz and Barrymore both arrived at the Globes bash held inside the hotel's swanky bar/restaurant but ignored each other all night long. For two friends once attached at the hip, insiders say the tension wasn't hard to spot.

"Both Cameron and Drew were at the party but neither one spoke to each other!" a fellow party goer tells OK!.  "They were on opposite sides of the room the entire night."

Has Cameron ditched her friends for her man? Cam and Drew, who became best friends while filming Charlie's Angels, were once each other's sidekicks, accompanying each other out to clubs and parties. But now that Cameron has been seriously dating model Paul Sculfor, she's rarely seen without him.

An eyewitness tells OK! that "At one point, Leonardo DiCaprio saw Cameron coming towards him and he immediately made a U-turn and walked in the opposite direction."

Looks like lines are being drawn!