After a day of frolicking at Malibu beach in just her underwear, Britney Spears has started work on her first music video clip in almost two years. True to form, when she stepped out of an LA warehouse between takes, there was again no shortage of skin on display - her tiny black dress barely covered her knickers. She also revealed every woman's enemy: cellulite covered thighs. Studded knee-high boots and pillbox hat completed the rather puzzling look, and it was clear that her aversion to wearing a bra is still going strong. Britney is hoping to keep details about her new project quiet, but reports suggest that the video will be for new song titled "Get Back." The singer, who is choreographing all the moves herself, recently put a call out for extras who were "attractive, hip and enthusiastic to act as bar patrons. According to reports, the 12-hour day was "pro bono" but Britney did at least pay for all the food. Her representatives have so far not commented on this latest comeback move Meanwhile, the troubled star has received words of support from former pop rival and Mickey Mouse Club alum Christina Aguilera. Aguilera, who is reportedly expecting her first child with husband Jordan Bratman, has defended Britney's parenting skills, according to reports. She told the Daily Star: "Britney is a good person and a good mom. She's been under so much pressure since she was a child" "I don't think any of us should judge her or jump to conclusions. She loves her boys and they're turning out great."