A top Nxivm “slave master” recounted on Friday her 17-year relationship with leader Keith Raniere — and how he manipulated her with sex and empty promises of having children together.

Lauren Salzman said she was fully devoted to Raniere after their relationship began in 2001, even though he openly slept with other “slaves” who were also part of Nxivm’s secret sorority DOS.

“For me, it was a monogamous relationship,” Salzman testified in Brooklyn federal court, where her ex is on trial for sex-trafficking charges.

She said they stopped being intimate around 2008 or 2009 — when the alleged sex cult was in full swing.

As their affair slowly crumbled, she sought to break things off with Raniere for good in 2013 after reuniting with a flame from high school.

But Raniere had other ideas.

“He told me that if I stayed,” the now 42-year-old recalled, growing red-faced and emotional, “he would invest in our relationship and we would have children.”

The couple, however, never did.

Salzman, the daughter of Nxivm co-founder Nancy Salzman, disclosed other disturbing details about her time with Raniere, saying he controlled her every move — and body.

“He thought a good weight for me would be around 100 pounds,” she said.

He snapped naked, up-close photos of her private parts and forced her into partaking in threesomes with other alleged slaves, including “Smallville” star Allison Mack.

“Initially, I participated because I was curious,” she said. But later she said she gave in to the romps because “he wanted that.”

Raniere was not only controlling, he was wildly jealous, too, Salzman recalled.

In 2011, she was forced to draft a “7-point breach plan” as punishment for jumping on another man during a group volleyball game.

Raniere, known to DOS “slaves” as “grandmaster,” was furious.

“He said, ‘You straddled him,'” Salzman said.

In her “plan,” she conceded, “I’m perceived as easy or available.”

“This degrades me and sets a bad example for the organization and reflects poorly on Keith and his choice to be with me,” the “plan” also said.

She told jurors, “I saw myself as dysfunctional.”

Raniere even managed to lord sex over Nxivm’s lesbian members and was deeply offended when a couple looking to conceive sought an anonymous donor instead of asking for his sperm — even though he planned to reject the request anyway.

“He didn’t understand why she didn’t want him as the donor,” Salzman testified, referencing a woman identified in court only as Sioban.

Salzman recalled that Raniere at the time even touted that his spawn would receive reduced tuition to Nxivm’s pricey children’s learning center, called Rainbow Cultural Gardens.

“His children would have 50% off on that,” she told jurors he’d said.

Salzman and five other Nxivm cohorts, including Raniere, were arrested in 2018 in a federal takedown of Nxivm, which billed itself as a self-empowerment organization.

In March, she quietly pleaded guilty to racketeering and racketeering conspiracy and agreed to cooperate with prosecutors.