Jason Wilder / Retna Ltd.
Jason Wilder / Retna Ltd.

Jessica Simpson isn't ready to show off her bikini body just yet.

The 28-year-old singer -- who was scrutinized earlier this year for appearing curvier than before -- kept her body covered up as she tanned poolside in Cabo San Lucas, Mexico, Thursday with her friends and mother, Tina.

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As she and her pals soaked up the sun, Simpson draped herself in a wrap and towel. She was also spotted in a baggy green smock,.

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Rascal Flatts singer Jay DeMarcus - who recently wrapped up a tour with Simpson - tells the new issue of Us Weekly that the country crooner shouldn't be so shy about her body.

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"I didn't see an ounce of fat on that girl anywhere, and I saw her up close every night," he tells Us. "She's sweet."