Being held up at gunpoint isn’t the only thing Ryan Lochte lied to NBC about during the Rio Olympics.

Even though the swimmer told the network in a post-race interview that he was single, his new girlfriend — Playboy Playmate Kayla Rae Reid, whom he met on Tinder — was secretly in Brazil and cheering on her man.

“I was in Rio the whole time,” Reid told The Post. “We didn’t want people to know I was there, and I didn’t want to be a distraction.”

She was even in on Lochte’s fake claims of singledom.

“I agreed to everything. I was like, ‘[Our relationship is] fresh and nobody needs to know.’ The people that truly know us knew we were sickly [sic] in love.”

Since then, though, their relationship has moved as fast as Lochte does in the pool. In October, the scandal-plagued swimmer — who was recently voted off “Dancing With the Stars” — rented a helicopter in Los Angeles and proposed to his beloved. They’d known each other just under 10 months.

“Normally a married couple would go through what we went through over 20 years, but we’ve done it in [less than] a year,” Lochte, 32, has said, referring to his robbery lie being exposed — and the public backlash that followed. “That’s when I knew, I’m not letting this one go.”

So who is the self-proclaimed “private” beauty, and how did she land the party-boy Olympian?

A Virginia native, Reid, 25, is a former high-school cheerleader who admits to a botched boob job, swore she’d never date an athlete, and hid her nude career from her conservative family.

After high school she attended a few different colleges, waited tables and settled in LA. At the time, she wasn’t exactly Playboy material, she admitted: “I was always kind of chubby. I never watched what I ate.”

But after a bad breakup, Reid dropped 20 pounds. She started hitting the gym, adopted a vegan diet, and gained a newfound confidence when she was hired for modeling jobs and promotional work for brands like Monster Energy. Then, two years ago, Playboy called.

“I was like, ‘I don’t think so,’ ” said Reid. “My family is very Republican, traditional and Southern. I sat the whole family down and I was like, ‘So I got an offer to be a Playmate centerfold.’ My grandmother was like, ‘You have to do it. We just won’t tell the family in Alabama, you know what I mean?’ ”

Reid was Miss July 2015 — appearing three months before the magazine announced it was ditching its legendary nude photos. But she admitted that there is one thing about her centerfold that still haunts her: her double-D breasts.

“The one thing I wasn’t proud of was that I had a bad boob job. They were just way too big for my body. They were completely Playboy, rock-hard [breasts],” she said. “I wanted small, kind of saggy, pretty [breasts].”

Reid’s doctor agreed they weren’t quite right, so he corrected them for free. A week later, she connected with Lochte on Tinder. The two then met in person at Hollywood’s Bootsy Bellows, a burlesque-themed nightclub co-owned by David Arquette. The way Reid tells it, their January meet-cute was straight out of a romantic comedy.

“We physically ran into each other. We grabbed each other’s hands and were looking into each other’s eyes. We clicked,” she said. “I had always heard he was a player and a partyer. I always said I would never date an athlete. When I met him, he was the complete opposite of everything I thought he was.”

Besotted, Reid packed up her LA apartment in early April and moved close to his training facility in Charlotte, NC, to be with him before the Olympics.

Their relationship was tested when Lochte told NBC that he and fellow swimmers had been robbed at gunpoint in Rio on Aug. 14. It was soon revealed that they actually stopped to use the bathroom at a gas station and were accused of vandalism and public urination. The media turned on Lochte, who went into hiding.

Reid said that initially she did not know the details because she was unable to connect with Lochte, who was busy with various Olympics events. But when she found out about his lie, she wasn’t angry.

“I was just concerned . . . I wanted to be by his side,” she explained. “We’ve all peed in bushes. We all can say, ‘I made a mistake while intoxicated.’

“I’ve tried to remind him, ‘You don’t get to live like a normal person. Every mistake you make . . . you live under a microscope.’ But it’s done now and it’s something he has to overcome.”

The pair have put the scandal behind them and are looking toward the future: house-hunting in LA and wedding planning, something Reid never thought she wanted.

“I never pictured myself married to anyone,” she said. “I just never imagined that.”

Lochte changed all of that. “He’s so romantic. He leaves me love letters all around the house. He is a softie. He’s sensitive and thoughtful.”

He also won her over with his desire to be a father. Reid, who doesn’t have much of a relationship with her own father, was deeply moved. “He wants kids so badly. That is what made us connect,” she said. “He said his one goal in life was to be a great dad.”

And the Playmate won’t rest on just being Mrs. Lochte. She’s still going on modeling and acting auditions and hopes to land a spot in the Sports Illustrated Swimsuit Issue while forging her own path.

“I’ve worked so hard on my own, not getting a penny from my family,” she said. “I don’t want my hard work to be forgotten.”

This article originally appeared in the New York Post's Page Six.