Paige DeSorbo, top left, Kyle Cooke, Jordan Verroi, Lindsay Hubbard, Hannah...

Paige DeSorbo, top left, Kyle Cooke, Jordan Verroi, Lindsay Hubbard, Hannah Berner, and, bottom row, left, Amanda Batula, Carl Radke and Danielle Olivera are the resident of "Summer House." Credit: Bravo / Karolina Wojtasik

The “Summer House”-mates head to the Hamptons for a third season of weekend frolics as the Bravo reality show returns Monday at 10 p.m. with a trio of new cast members, including Hannah Berner, a longtime part-time Shelter Islander.

“We were just celebrating my mom’s birthday there” last month, says Berner, 27, speaking of Lenore DiLeo-Berner, principal of Middle School 51 in Park Slope. Shelter Island, where Brooklyn native Berner has summered all her life and where her parents and her paternal grandfather each owns a house, “is where we celebrate things as a family.”

And “Summer House” will celebrate family things. “My grandpa, who’s hilarious, will be on,” Berner says, referring to retired high-school basketball coach Jerry Berner. We’ll also see her maternal grandmother, Vera DiLeo of Middle Island; dad Dan Berner, who lives with Smithtown native Lenore in Long Island City; and brother Dan, a 25-year-old financial analyst. (Her mother, for professional reasons, will not appear.)

Berner acknowledges her vacations on Shelter Island were not the stuff of “Summer House,” in which a group of Manhattan professionals — with other newcomers Paige DeSorbo and Jordan Verroi joining past seasons’ Kyle Cooke, Amanda Batula, Carl Radke, Lindsay Hubbard and Danielle Olivera — drink to excess, hook up with one another and engage in soap-opera dramatics.

On Shelter Island, “I like to relax and play tennis, play golf. I’m like a retired old man in a 27-year-old body!” Berner jokes. She enjoys golfing with her grandfather and his friends, and eating with them afterward. “They call themselves the Romeos: Retired Old Men Eating Out,” she says affectionately. “So going to the Hamptons to hang out with people my age was a fun new experience.”

All three newcomers to the house on Deerfield Road in Water Mill worked at the media and marketing company Betches, where Berner, until striking out on her own in December, produced videos. They were part of the same social group as the “Summer House” veterans.

“I met Carl, I met Lindsay and I knew of the other people,” Berner says. “My name just kind of got thrown into the mix. Then I got a call where [the producers] get to know you and see if you have chemistry with the rest of the group. Or bad chemistry — I don’t know what they’re looking for!” she says, laughing. “I had just come out of a yearlong relationship that was the hardest breakup I’d ever had. I just wanted a new experience.”

Berner, a former juniors pro tennis player who made headlines as a high schooler playing for the boys’ team at Manhattan’s elite The Beacon School, concedes that the show’s on-air discourse consists mostly of gossip and sniping at each other. “We’re filmed 24/7,” she says, “so if we’re talking about art or architecture, which we probably weren’t, it didn’t make the cut. People aren’t watching the show for that.”

The drama gets lubricated by alcohol, but not, Berner attests, at the producers’ behest. “When we go to a restaurant they provide us with two drinks. The rest is on us to pay for out of our own pockets” if they so choose.

Berner, who runs the podcast “Berning in Hell,” calls “Summer House” “a coming-of-age show” though the cast, at 25 to 35, seems a bit old for that. Still, she says, “I grew up through the show, because I never would have had these kinds of experiences. I really did mature through the trials and tribulations of shooting it.”

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME