Paula Rosado normally doesn’t rent out her Hamptons home in the off-season. That’s family time. But last October, Rosado, a marketing professional from the New York fashion world, was approached by a sure-bet tenant who was eager to rent her modest, 1890s, shingled three-bedroom Sag Harbor home through the end of April—a local Realtor named Jonathan Davis.

When it comes to Hamptons real estate, Davis—who currently has at least $70.5 million in sales to his name as an agent for the luxury realty group Nest Seekers International—is descended from royalty. He’s the 30-year-old son of Tim Davis, a Hamptons real-estate titan with more than $4 billion in sales to his credit. So it was with that in mind that Rosado signed over her house to the bearded young Davis, who offered to write up the lease himself. Normally Rosado would never let a tenant handle that task, but why not? He was a professional (the son of that Davis). And besides, “I’m a local,” he told her. “I’m not going anywhere.”