It sure is a tight market in the Hamptons.

Those demanding “the tightest vagina” on the East End are shelling out tens of thousands for the privilege of a private house call (or even a yacht call) to get it, a gynecologist told The Post.

Size has always mattered in one of the world’s richest summer playgrounds, but now it’s the women –from sex-obsessed housewives to husband-hunters to swingers — demanding peak sexual performance.

“We know men like to have the biggest penis, but now women” are demanding to upgrade their sexual equipment, said Dr. Amir Marashi, a designer gynecologist who recently opened his first Hamptons office in Sag Harbor to kick off summer season.

“I want to have the tightest p–sy in the Hamptons,” one patient declared to the unfazed doc, who caters to jet-setting patients around the world, making house calls to mansions and castles or the yacht via private helicopter — for a minimum of $20,000, he said.

Wild Hamptons sex and swinger parties demand nothing less than confidence-boosting tuneups from G-zone injections for better orgasms, to mini-vaginoplasty for a tightened vaginal canal and surrounding muscles. 

The board-certified gynecologist boldly declared, “I promise you’ll have the best orgasms in the Hamptons.”

But life isn’t always easy being a “vagina whisperer,” says the 47-year-old cosmetic surgeon.

Patients have propositioned him for sex “too many times” – inviting him to test his work personally, which the married doc insisted he always gently declines.

“Somebody may feel, ‘Well, he’s a doctor’ or ‘he’s a vagina whisperer,’ but it’s absolutely a no-no,” insisted Marashi, an Iranian native whose father was a surgeon.

For his royal patients who have more than one wife, there’s even a little healthy competition between the multiple spouses.

After attending to the “wife of a minister in Dubai,” Marashi said he received a flurry of unusual requests.

“Four other women come and they’re all his wives and each of them would say, ‘I wanna be the tightest one,’ ‘I wanna be the tightest one,’” the doc recalled.

As the Hamptons season gets in full swing, Marashi is prepping for a yacht call. “I’m doing orgasm injections for a guy, his wife, and I believe his wife’s girlfriend,” said the doc who recommends immediate sex sessions to activate the recharged organs.

Still, discretion is critical for his Hamptons patients.

One patient “didn’t want me to go to their house from the front, so they wound up sending a boat for me docking right into the back entrance,” he said.

One patient says the treatment changed her life — and her sex life.

“I literally tell him he took me from point A to OMG,” longtime patient, Michelle, gushed to The Post. After “strong” exosome treatments derived from stem cells, she heard “angels singing during sex,” the kind of pleasure “I only read about.”