They had a loving marriage and their sex life was great. Here's why they started swinging.

Simon and Carolyn Hopper – a Southampton, U.K. couple – always had a healthy sex life. When Simon's mom got sick, though, they began traveling to see her before she died in 2016 and listened to plenty of podcasts and eventually started watching documentaries about sex and polyamory. The pair later took a vacation and joked about the other couple by the side of the pool lathering each other up with sun block. Were they swingers? They certainly acted overtly romantic.

"You just don't really see that so much over here in the U.K.," Carolyn Hopper, 50, says.

The woman made a pass at Simon, who rebuffed her. But Carolyn took her up on it, which started a fight between the Hoppers.

"When we came home, we started talking about whether this is something that we wanted to explore because (Carolyn) always said that (she was) bisexual, but we'd never looked into that as a thing that we could do together or whatever," Simon says. He went into research-mode to learn everything he could about non-monogamy.

"I just sat back quietly and waited for him to feel ready to explore it," Carolyn says. "I didn't really need to research or do anything, because in my simplistic view, it wasn't really anything I wanted to understand further." She knew what she liked: "My mind couldn't understand why he wasn't just open to a bit of fun after a few drinks on holiday in the sun. I was like, 'what's not to like? It was two women and you.'"

The Hoppers now host the aptly-titled Bed Hoppers podcast. But they want you to know their view of swinging goes beyond sex. "Our approach is very much about creating friendships with benefits," says Simon Hopper, 46.

More and more swingers have been vocalizing this mindset, insisting they are not a seductive, sensationalized monolith.

"Often the people that you meet, you don't always have sex with them, you just make really good friends, and you can be open with them," Simon Hopper adds.

What is swinging, exactly?

Swinging is the practice of exchanging partners for sex, according to a 2014 article in the Electronic Journal of Human Sexuality. It's unclear how many partake in swinging today – some estimates have said 2% or less – though one study from the North American Swing Club Alliance said 15% of U.S. couples have tried it at least once in their married lives.

But every person – and every couple – works differently, a critical piece to remember when thinking about any kind of relationship.

'It took us a long time'

The Hoppers eventually figured out what works for them after starting to look for others to sleep with. A date with a woman here, swinging clubs and parties there.

"It took us a long time to find people that we liked," Simon explains. They even started hosting their own events.

"There's no naughtiness. It's all, what we'd say, 'above board,' Simon adds. "If you're new, you can come along and find out about the lifestyle. Or you can come along and find people to hook up with at a later date or later that night when our event has ended."

But these relationships don't always have to lead to sex. "Because you're all in the same environment, you're all talking about sex, you're all open about it. So actually, the conversations with people that you meet through this approach become much more interesting or have the possibility to be more interesting than your normal friends."

'Pants on and pants off friendships'

Cate, who requested her last name be withheld for privacy reasons, is an Australian swinger, who lives in the Netherlands with her partner Darrell and co-hosts the Wanderlust Swingers Podcast. She describes their lifestyle as "socio-sexual or social swinging." What that means: "Unlike some who may prioritize frequency, we emphasize the importance of mental and friendly connections before delving into sexual activities with others." In other words, "pants on and pants off friendships."

This helps the pair maintain a relationship style that works for them no matter where they are – from Australia to the U.K. to the U.S. "This flexible approach allows us to engage in the lifestyle around the world, fostering meaningful connections while enjoying the freedom to participate as we please," she says. They've been to more than 30 countries, immersing "ourselves in various swingers clubs, events and resorts, gaining a global perspective on the diverse approaches to swinging."

Like any community, swingers are not all the same. "While some prioritize and actively seek out emotional connections, others embrace the spontaneity and thrill without necessarily seeking social bonds," Cate says.

More on this topic: Swingers want you to know a secret. Swinging is not just about sex.

'Swinging won't fix a broken relationship'

How do you know it's for you? "Opening up a relationship works best when the relationship as it is feels stable, honest, and communicative," Allison Moon, author of "Getting It: A Guide to Hot, Healthy Hookups and Shame-Free Sex," previously told USA TODAY. "Swinging won’t fix a broken relationship, but it can add new adventure and excitement to already solid ones."

Cate adds: "Communication and mutual understanding are key. We make a conscious effort to maintain these connections by regularly connecting with friends through platforms like Zoom, making time for international travel to visit each other, and cherishing moments together."

Remember, too, that swinging will not be for everyone – and may not be for you. Cate says: "The foundation of any relationship is built on consent, communication and respect. Engage in open and honest discussions with your partner, acknowledging that choices in intimacy are personal and should be mutual."

In case you missed: The swinging community hid in the shadows. Then came #SwingTok.

This article originally appeared on USA TODAY: Swinging, non-monogamy: Emotions, sex in nontraditional relationships