D'Agostino, 50, and Rothschild, 52, were caught in the Hamptons together over the Labor Day weekend, while de Lesseps, 52, was alone in Sag Harbor.
Rothschild and de Lesseps were friends for years prior to the RHONY star's New Year's Eve wedding , and her nuptials could have ended their relationship. Their last photo together was a year prior to the Palm Beach, Fla. celebration.
"Anna has been friends with Tom for 12 years," an insider told Radar. "She hates Luann!"
Rothschild isn't the only girl D'Agostino has been wooing since he filed for divorce from de Lesseps in August. Radar caught him cozying up to a woman at a local New York bar just hours after splitting from his reality star wife, and again with another blonde just weeks later.
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