Aside from an occasional towel, you'll be hard pressed to find a stitch of fabric on the hundreds of people lounging in and by the pool at this Jamaican resort. For the most part, people congregate in groups in the water or the swim-up bar, chit-chatting and swapping stories as any vacationers might, though perhaps with a bit more revelry and boisterousness.

Off to the side, though, it's not entirely uncommon to see a couple—or sometimes a group—engage in behavior that's…a bit more intimate. And no one around them tends to bat an eye. It's just another day at Hedonism II.

One of the side effects of America's growing acceptance of adult entertainment and comfort with its own sexuality is sex-focused side industries are seeing growth as well, including sexually-charged vacation destinations.

Traffic at Hedonism II has been on a steady rise since 2013, when Harry Lange, a former fund manager at Fidelity Investments, and a group of associates bought the resort. At the time, occupancy of the 280 room resort was hovering at 53%. In 2015, it hit 67%, climbing to 68% in 2016. This year, says Lange, it will top 70%.

"I think this generation is more sex-oriented than the one before them in the Reagan years," says Lange. "Kids were more conservative then, but … kids in their 20s are seeing more freedom again. We're seeing several young groups coming each year."

A bit closer for some U.S. residents is Mexico's Desire Resort and Spa on the Riviera Maya. The couples-only resort is, like Hedonism, an all-inclusive, clothing optional establishment that is popular with exhibitionists and swingers. (One of Desire's most notable attractions is the "Sin Room," where sexual activity—among groups and couples—is common.)

For those who prefer to keep their sex vacations a bit more private, there's KinkBNB, an Airbnb-like site that lets people rent out homes or rooms that cater to BDSM enthusiasts (a number that has been growing since the release of 50 Shades of Grey). The houses on the site tend to feature pleasure rooms and dungeons that many people in that lifestyle would like to explore, but either can't afford or can't have in their own homes due to children, frequent visitors and so forth.

KinkBNB came about after the friend of one of the co-founders was booted off Airbnb for advertising her 'dungeon.' Once the alternative site was live, she told friends in the San Francisco BDSM community about it and within an hour, 100 people had signed up. Today, the site has between 25,000 and 30,000 users.

"We provide a marketplace for people to rent their spaces out in an environment where it is acceptable," says Matias Drago, the company's co-founder. "We have a community of people that embrace [the BDSM lifestyle] and want to share their spaces with other like minded folks."

The site offers approximately 330 listings in more than 50 countries including the U.S., Brazil, and France. Some rentals offer daily rates, others charge by the hour.

"Unlike a typical Airbnb or vacation rental, a lot of time the hosts don't want the overnight guests in their spaces," says Drago. "They vary from a room in someone's house or apartment all the way to a more commercial setting. Some of our dungeons are several thousand square feet."

Sex tourism (and we're not talking about illicit trips to Thailand) isn't exactly a new thing. For instance, several operations offering fans of adult entertainment the opportunity to visit the set of a porn film have opened—and subsequently closed—in recent years. But what make today's offerings different is the shift from spectator to participant.

At Hedonism, visitors stay for an average of eight days, says Lange, though it's not uncommon for that to extend to 10 or 12. And while there certainly has been an influx of younger visitors in the past couple of years, the average age of visitors is 48.

That's generally when kids start leaving home for college or their own lives, or at least are old enough for the parents to leave them with friends or loved ones for a period, says Lange. That freedom lets couples add some spice to their relationship. And while the resort is often viewed as a hub for swingers, monogamous couples rarely feel pressure.

"It's almost total freedom," he says. "You can do whatever you want –whether you're big into the lifestyle [the preferred term of couples who swap partners] or you like being in a sexually-charged environment. About one-third of the people who come are swinger types. Another one-third are voyeurs or might try a little bit of something. And one-third don't do any of that. The good news is there's no pressure to do that, because the swingers can easily find someone else there."

SOURCE:fortune.com/CHRIS MORRIS