The 55-year-old actress has struck up a romance with the 46-year-old real estate entrepreneur, who owns the 31,000-square-foot East Hampton Studio and Enclave Inn hotel in the exclusive Hamptons seaside resort just outside New York City, reported New York Post.
Stone was first linked to Michael in April when they were spotted together at the Creative Coalition banquet in Washington, DC, and have reportedly developed a close bond over the past couple of months.
"They are really good for each other," a source said.
The actress split from Argentinean model Martin Mica, 27, in January after an eight month courtship.
Stone has three adopted sons, 13-year-old Roan, whom she adopted with ex-husband Phil Bronstein, as well as Laird, eight, and Quinn, six.