Cameron Diaz bravely smiled for the cameras at last night's premiere of What Happens in Vegas, in her first red-carpet appearance since her father's untimely death just weeks before. With her co-star Ashton Kutcher by her side, Cameron, decked out in a cute, colorful body-hugging dress and black heels, waved to the crowd of well-wishers as she walked the red carpet into the Los Angeles premiere. Cameron was absent from the London premiere of the movie while mourning the sudden loss of her dad, Emilio Diaz, who passed away on April 15, at the age of 58, after post-influenza turned to MRSA pneumonia. Understandably, she's still not ready to party. While Ashton and the likes of Eva Longoria Parker and Vince Vaughn headed over to the Whiskey Blue at the W Hotel, Cameron skipped the after-party festivities.