Exclusive: Turlington, 44, Smolders in New CK Ad

Supermodel Christy Turlington Burns is back and flawless as ever for Calvin Klein's latest collection of sleek, sexy intimates, and only ET is with the 44-year-old stunner as she strikes a pose for the iconic brand against the backdrop of picturesque Puerto Rico.

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Shot by famed photographer Mario Sorrenti, the Fall 2013 underwear campaign features Burns, who first repped the brand 25 years ago, sporting CK's matching black bra and panty set, speaking sexily into the camera.

"Clothes tell a story. Sometimes it's true; sometimes it's what you want people to think," coos the impossibly fit mother of two in the black-and-white video. "But this says what I really feel. It's not a secret, just personal. You might be surprised."

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Click above to see Burns in action! Plus, watch behind-the-scenes footage and interviews on location in Vieques, Puerto Rico wherein the supermodel talks about re-teaming with Calvin Klein, her documentary films and recent Every Mother Counts campaign, benefiting the health and well-being of girls and women worldwide.