Justin Timberlake was in the Hamptons, singing and dancing for a crowd including Alicia Keys, Jamie Foxx and Pharrell Williams (to whom Timberlake later bowed while sharing the stage) at Ron Perelman’s annual Apollo in the Hamptons bash Saturday night.

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Lady in red Beth Stern celebrated her annual swimsuit spread, shot by husband Howard, in Social Life Magazine at a private Southampton estate Saturday. The soiree included a seafood feast by Hawaii’s Turtle Bay chef James Aptakin, who was flown in to cook for the occasion. Always a pro, Beth Stern posed for photos and put on a smile — hours later, the animal rights advocate posted on social media about the passing of her beloved cat, Charlie.

It was a huge book bash to benefit the East Hampton Library. Celebrity scribes and best selling authors including Laurie Gelman (whose husband, Michael, took photos), News 12 Long Island’s Stone Grissom, Elizabeth Vargas, Stephen Kennedy Smith, Dick Cavett, “Ladies of London” star Marissa Hermer, celebrity chef Alex Guarnaschelli, Jessica Seinfeld and six-time Emmy winner Alan Alda did a massive meet and greet at Author’s Night. It was a side-by-side signing session for Alec and Hilaria Baldwin who admitted they haven’ t read each other’s books.— Elisa DiStefano