(CNN) Revelers in the rainbow-washed crowd smiled and cheered as the little blond girl in the parade float pageant-waved to the B-52's "Love Shack."

Next to the float, the girl's father, Billy Holder, handed out fliers to the Atlanta Pride Parade crowd. His wife, Melissa, carried a banner along with Jeremy Mullins, the couple's partner.

"Polyamory: Having simultaneous close emotional relationships with two or more other individuals," read their purple-lettered banner , embellished with an infinity heart.

The "awws" and waves from the crowd gave way to some puzzled looks and snickers.

"Multiple partners?" the man next to her guessed.

Sort of. As the concept of open relationships rises in pop culture and political debates, some polyamorous families like the Holders and Mullins see an opportunity to go public and fight stereotypes that polyamory is just swinging, cheating or kinky sex.

It's not just a fling or a phase for them. It's an identity. They want to show that polyamory can be a viable alternative to monogamy, even for middle-class, suburban families with children, jobs and house notes.

"We're not trying to say that monogamy is bad," said Billy Holder, a 36-year-old carpenter who works at a university in Atlanta. "We're trying to promote the fact that everyone has a right to develop a relationship structure that works for them."

For the Holder-Mullins triad, polyamory is three adults living in the same home about 20 miles south of Atlanta. They share bills, housework and childcare for their 9-year-old daughter. They work at the same place, sharing carpooling duties so someone can see their daughter off to school each day.

Surrounded at the parade by drag queens from El Gato Negro nightclub, singers from a gospel choir and supporters of the Libertarian Party of Georgia, Billy Holder didn't stand out in his jeans, T-shirt and wide-brimmed, sun-shielding hat. That's sort of the point, he said: to demonstrate that polyamorists, or polys, are just like anybody else.

But, he's quick to add, "It takes a lot of work and it's not for everybody."

It's a common refrain from long-practicing polys. Jealousy among partners is one thing, but they also face or fear disapproval from neighbors, relatives and coworkers. The Holders and Mullins dealt with rejection from parents and one of Melissa Holder's sons when they revealed their relationship. They've also been the subject of a child welfare probe that ended in no charges being laid.

"We've been through it all," said 35-year-old Jeremy Mullins, a computer programmer.

That's why they're coming out , he said -- to change the status quo. And yet, their willingness to speak with CNN over the past 18 months came with conditions, such as the request to not name their employers.

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Marching in the parade for the fourth year is just one way they're trying to promote public acceptance of polyamory. Someday, they want to challenge laws that criminalize adultery and cohabitation, Mullins said.

"We want to promote the idea that any relationship is valid as long as it is a choice made by consenting adults," he said. "In this regard, and as in most things, promoting public acceptance is the first step."

It's an uphill battle. Many traditional marriage counselors and relationship therapists discourage non-monogamy, and in the absence of more research on the long-term effects of polyamory, modern science and academia hasn't reached a consensus on whether it's a healthy relationship structure.

Even among a crowd as colorful as the Pride Parade, the giggles and questions suggest polyamory is still a way of life that's on the fringes.

'Polyamory ain't for sissies'

According to the flier Billy Holder handed out at the Pride Parade, which borrowed from The Polyamory Society and More than Two , there are many ways to define polyamory.

"Polyamory is the nonpossessive, honest, responsible and ethical philosophy and practice of loving multiple people simultaneously," it said.

"Polyamory is not a swing club or group."

"Polyamory is not about recreational or promiscuous sex."

Otherwise, there are no universal rules for "how it works," one of the most common question polys say they hear, Holder said. The most common dynamic tends to start with a couple, married or unmarried, who might identify as straight, gay or bisexual. Guidelines are set within each relationship -- ideally, a negotiated framework of communication based on trust and honesty, he said.

For each of the 12 people walking with the Holders-Mullins triad in the Atlanta Pride Parade, polyamory works differently. For example, Mark, a tall, bespectacled computer programmer, has been happily married to his wife, an electrical engineer, for more than a decade. They live alone and have no children, but they've been involved with two other couples with children for the past six years. Mark and his wife spend time with the adults and their children doing family-friendly activities but the adults also go out on dates, cuddle and more.

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It's not cheating or swinging, he said, because everyone knows about other partners, whom Mark calls his girlfriends. There is a level of intimacy and emotional attachment that makes them more than friends with benefits or one-night stands, he said.

"I'm more involved in their lives and more aware of their inner thoughts or aspirations; I'm more involved in their long-term happiness," said Mark, who asked not to use his last name out of concern that he and his wife might face backlash from employers.

A diagram of Mark and his wife's relationships.

"It's like having a regular, monogamous relationship but having more than one of them."

It's unclear how many people identify as polyamorous because, like Mark and his wife, the majority aren't open about their relationships. Because of the varied forms these non-monogamous relationships take, it's difficult even to know who to include in such a count, demographer Gary Gates said.

"It's not completely clear how you would measure this group, since I'm not sure there's a common terminology around how individuals in polyamorous families identify their relationships to each other and their children," said Gates, a demographer at the Williams Institute , which conducts research and policy analysis regarding legal issues that affect LGBT populations.

Sheff based her findings on 15 years of research that began with a partner's request to explore alternatives to monogamy. She continued her research even after her relationship ended, and does not consider herself a polyamorist. But her research led her to believe that polyamory is a "legitimate relationship style that can be tremendously rewarding for adults and provide excellent nurturing for children."

Making it work, she acknowledges, is "time-consuming, and potentially fraught with emotional booby traps," she writes. It can be rewarding for some "and a complete disaster for others."

While some scientists say monogamy is probably not humans' natural state , and is instead likely a social construct, many therapists say learning to control sexual impulses toward multiple people is a hallmark of emotional maturity.

More often than not, non-monogamy leads to the demise of relationships, said Karen Ruskin, a Boston-area psychotherapist with more than two decades of experience in couples counseling. Instead of focusing on the primary relationship, partners are turning to others for fulfillment.

"Even if non-monogamy is consensual, it's still a distraction from dealing with each other," said Ruskin, author of " Dr. Karen's Marriage Manual ."

"It all goes back to choice. Non-monogamy is choosing to be with someone else instead of being attentive to your spouse when the relationship is troubled."

Couples can establish rules and parameters to limit jealousy, she said. But in her experience working with couples, "those rules never end up working out for everyone," she said.

"It has shown to be damaging and destructive to a person as an individual, to the couple's relationship and the family unit as a whole."

Indeed, while many associate polyamory with swingers or kinksters, "there are much easier ways to get laid," said Anita Wagner Illig, founder of online polyamory resource, Practical Polyamory

Wagner Illig, a self-appointed "poly educator" who gives talks at adult conventions about polyamory, began to identify as poly after her second divorce in the late 1990s. She decided there must be a better way than cheating to have multiple relationships.

Wagner sees this year's U.S. Supreme Court ruling on same-sex marriage benefits as a sign that society is becoming more accepting of "other kinds of relationships," she said.

But like many in the poly community, she stops short of believing it could pave the way for multiple legal marriages. Many aren't looking for multi-partner marriage, anyway, she said -- they just want to feel free to have relationships currently outside the norm without being judged as freaks or outcasts.

"Polyamory," Wagner Illig warns, "ain't for sissies."

'The poster family for poly'

Billy and Melissa Holder met in 1997 at CoastCon, an annual science fiction and fantasy convention held in Biloxi, Mississippi. They were seeing other people in monogamous relationships but Billy thought she was funny and cool. They reunited at the next year's con, developed a monogamous relationship and married in 1999.

An open relationship first came up in discussion the next year, after cheating allegations against a relative rocked the family. They didn't know the term "polyamory" until years later, but already saw an opportunity to invite more people into their lives. Billy Holder had always believed that he was "different," that he wanted to date more than one person at a time, but he wanted to do it with his partner's knowledge and consent.

"We wanted to be able to be fully honest with each other and trust each other," he said. "One of us said something to the effect of 'Why cheat? If you find someone you are interested in, just talk to me about it.' We are adults, there is no reason we can't be honest with each other."

They decided they were free to date people they met at cons and parties, as long as they told each other. At fan conventions, they'd designate a night for going out with others, with a few straightforward rules: Be safe, be home by dawn and don't do anything I wouldn't do. Unprotected sex was off limits. If the relationship appeared to be progressing, they would talk about the need for introductions. If the new person had a partner, he or she needed to know, too.

It wasn't all bliss, especially in the beginning. Sometimes, Billy would "surprise" Melissa with stories of his exploits before she knew he was seeing someone, or he would bring someone home in the middle of the night.

Still, they continued, and formed their first triad in 2002 with a woman Billy met.

"We all relied on each other emotionally for support," Billy Holder said. "We didn't live together, but we were close, we were a unit. When we were together we did everything together."

They learned that polyamory takes a lot of negotiating to keep jealousy at bay. The Holders don't like the word "rule" because it sounds rigid, they said, but if there is a rule, it's "better to ask permission than forgiveness."

In April 2008, Billy met Jeremy Mullins through a mutual friend on a camping trip. Holder describes himself as "emotionally bisexual." He wasn't sexually attracted to Mullins, but found emotional intimacy with him.

Months later, Melissa met Mullins at a gaming convention. The three bonded as a team in a Rock Band tournament. They met again at Atlanta SantaCon -- an event where adults party while dressed like Santa -- and invited Mullins to Billy's birthday party on New Year's Eve 2008.

"I went to that birthday party and basically never left," Mullins said. He became a regular fixture in the Holder home, making regular trips from Alabama to spend the weekend with them.

Still, it wasn't easy. Jeremy wanted more time alone with Melissa. If Melissa and Jeremy saw a movie on their date night that Billy wanted to see, he'd get upset. Jeremy felt like he wasn't experiencing the mundane aspects of family life, only the "highs and lows."

"The little things that we didn't talk about, they built up like a pressure cooker and we'd have a fight every six weeks or so," Billy said. "We realized we needed to do a better job of communicating what bothered us when it bothered us."

They fine-tuned their communication, and decided their future should include Jeremy, full-time. Billy Holder bought a 4,000-square foot foreclosure in Fayetteville, Georgia, where they moved in 2012. To ensure they don't run afoul of Georgia bigamy laws, they each have their own rooms, but often share beds at night.

Billy Holder and Mullins aren't sexually involved, except on occasions when all three are together, "but we are emotionally intimate and share everything on that level," Mullins said. "We share everything that any other couple would."

They're partners around the house, too. Billy is the cook. Jeremy and Melissa clean up. When Melissa grew tired of doing the laundry, she spoke up and they switched roles. When Melissa participates in National Novel Writing Month each year, Billy makes sure she's plied with food and coffee while Jeremy hangs out with the kids.

"I think we're a little too boring to be the poster family for poly," Billy said over a lunch of Papa John's pizza at their home.

But being poly is nothing if not an ongoing work in progress. Melissa still gets annoyed when Jeremy leaves dirty plates in the sink, or when Billy goes on a tear over a new person he's met in a bout of what's commonly known in poly communities as "new relationship energy."

But now, she doesn't keep her frustrations to herself anymore.

"We talk early and often. Jealousy is usually fear dressed up as something else," she said.

In recent years, they've decided poly isn't an experiment -- it's a way of life. They wanted to create a close-to-home community where they could share and reflect on their experiences without being judged.

Walking in the Atlanta Pride Parade is just one way they're trying to step out in public and celebrate who they are. They've auditioned for multiple talk shows and a reality show, but have never made the final cut.

In 2010, they started the Atlanta Polyamory group on Meetup.com -- a website that makes it easy for people with common interests to find each other. The group now has more than 700 members among eight subgroups that extend far outside the city. In the past year alone, the group has more than doubled its numbers, a boost that Holder attributes to increased awareness of polyamory.

They also founded Atlanta Polyamory Inc., now called Relationship Equality Foundation, an advocacy group that hosts poly-focused retreats and gatherings.

They're trying to build a regional community outside the metropolitan hubs known for accepting alternative lifestyles. Other cities had conferences and meetup groups devoted exclusively to polyamory, so why not Atlanta?

'I wanted something better'

Last year, in a Holiday Inn Select just off the interstate, the Holders led the second Atlanta Poly Weekend, a retreat dedicated exclusively to poly-related issues. It drew people from across the Southeast and as far north as Baltimore.

Some attendees were single or relatively new to polyamory. A couple in their 20s described how they'd been together since their freshman year at Georgia Tech, had married a couple of years earlier, and had opened up their relationship after discussing how they still loved each other, but felt attractions to other people.

"He dates and I flirt but I haven't actively sought out dates. All that matters is that he's coming home to me," said the wife, Michelle, who asked to not use their last name because they haven't told their families.

A few attendees, like the Holder-Mullins triad, were married and dating and had at least one child. While parents attended panels, their children could stay at the "kid con" room in the care of a pair of women in a "closed quad" with their husbands.

"I've always thought it was better to live in a commune-type large family where you get to choose your loved ones," said Ashley Tipton, one of the moms in the quad from Marietta, Georgia. "I came from a broken home where I had to take care of my sisters and alcoholic mother and I wanted something better than that for me and my kids."

In panels with names like "Defining Our Relationships" and "The 5 Love Languages" -- based on Gary Chapman's bestselling book and relationship philosophy -- the discussions revolved around topics that often come up for monogamous couples: Communication, jealousy, time.

Some panels, though, were uniquely poly. One focused on legal issues, including a discussion of "Sister Wives" star Kody Brown's lawsuit to overturn Utah's laws against multiple people living together and "purporting to be married." A handful of states have similar laws in the books, including Georgia. Regardless of the case's outcome, "it's going to affect us," said the lawyer leading the session, who asked not to be identified.

U.S. District Judge Clark Waddoups heard arguments in January. Both sides are awaiting a decision on Brown's motion seeking to strike down the law as unconstitutional on a variety of claims, from free speech to free exercise to equal protection, Brown's lawyer Jonathan Turley said in an e-mail.

In a panel called "Coming Out," poly advocate Terisa Greenan led an animated discussion about the obstacles that keep people from telling others. Some polys hide their relationship from friends and family, fearing they could lose their homes or children. For many, religion was a common source of grief.

For some who were atheist, or practice paganism, being in a relationship with multiple people can seem even more unpalatable to people outside their religious or poly communities.

Jeremy Mullins, of the Holder-Mullins triad, was in the room for the discussion. He came out to his parents after he'd decided to move in with the Holders. His mother told him she feared for his soul, he said, and while he still speaks to his family, they have yet to meet the other people he considers family.

"It's about choosing between you and their god," one woman said. "My mom likes my boyfriends, but she hates my lifestyle."

"Yeah, people say they don't hate you, they hate the lifestyle," another woman added, "but I've decided I don't have to accept that. It's the same as hating me."

Meanwhile, at a panel called "Real Life Poly," about 30 people listened to Noel Roberston, also known as Ms. Noel, an adult sexuality educator active in Atlanta's kink community, dissect scheduling, jealousy and sex. Dressed in jeans and a zip-up sweatshirt and holding her newborn, she admitted that life outside the bedroom can seem pretty dull.

"Wednesday night belongs to Arthur, Thursday is Chris. Thank God for Google calendar," she said, eliciting nods from some, while others took notes.

Send reminder alerts to your partners when it's your night, she suggested. Dates don't have to be expensive or elaborate: Look for free concerts, or make errands into "micro-dates." Try sexting or Skyping or showering together. Drop the idea of what you think romance should look like and "find what works for you."

"It's hard enough in plain old vanilla relationships to keep romance alive," she said.

If partners don't like each other, or you don't like theirs, start talking, Roberston said. Figure out where veto power lies. Don't "play the one-up game." Stop evaluating who has better curves, bigger breasts, or who's the better cook.

"It's better to have the 'I'm scared' conversation than the laying down the ultimatum conversation," she said.

"What do you need to feel safe and secure?" she asked, inviting the audience to share. "It comes down to what do you need? What's important to you?"

Silence filled the room for a moment.

"I need to not come in last," one person said.

"I need time and space," another spoke up.

"I need to see that he can be independent."

"Support."

"That my partner knows where I'm coming from and has my back."

"Acceptance of all that I am."

'It's part of who I am'

Even years after Atlanta's first polyamory conference, acceptance remains an elusive goal. Most people watching the Atlanta Pride Parade this month tucked away Billy Holder's flier. A few took the time to read it, and came away with mixed reactions.

"I'm all for it if that's what you believe in," one 48-year-old man said.

"I've had friends in open relationships and it seems to work pretty well if they're open about their expectations," a 19-year-old woman said.

"I just don't know how it would work," another man added. "It must be confusing for the children."

"It wouldn't work for me," another parade-goer said. "I'm too jealous."

Getting ready for her star turn on the float, the Holder's 9-year-old daughter seemed oblivious to what others might think. Her parents haven't offered her a detailed explanation about their physical relationship; they don't think it's age-appropriate. But Jeremy has been in their lives since she was 4 years old, so she sees him as part of the family, if not exactly a blood relation.

"We know we have to tell her one day, we're laying the groundwork now for what and how we're going to tell her," Billy said. "For now, we emphasize to her that we all love her and we're all here for her."

When asked, she said "poly" means multiple partners, "loving many people."

"I'm happy because there's more people to ask when I have problems," she said.

She's proud to be at the parade, she said -- but if she could pick any float to join in, it would be the Atlanta Humane Society's. "I love animals," she said.

Her view seems consistent with her age, as sociologist Elisabeth Sheff writes in "The Polyamorists Next Door." In research and interviews with poly families, she found that children ages 5 to 8 didn't seem to care about how the adults related to each other, so long as they were taken care of.

Overall, they seemed to fare well as long as they lived in stable, loving homes. Living in a poly household didn't imply a child would prefer a poly lifestyle, she said.

So far, that seems to be the case with Melissa Holder's two sons from a previous relationship. The boys were 15 and 16 when the Holders sat them down and told them things were getting serious with Jeremy.

"We told them Jeremy was important in our lives in an emotional context," Melissa said. "We always had friends over and we're a huggy bunch. But this was the first time we acknowledged to them that a significant person in our life was going to be a significant person in our life."

The younger son didn't take it well and moved in with relatives in Louisiana. He declined to be interviewed for this story. Her older son, Sebastion, learned to live with the situation. It was an adjustment at first, he said, but it helped that the family had moved into a bigger home where everyone had their own space.

Mullins is "a generally cool guy," who suggests great books and talks with Sebastion about electronics, he said.

"It's like having a full house with someone else to talk to and help out with housework," said Sebastion, now 20 years and stationed in South Korea as a combat medic in the United States Army.

Sebastion tells friends that Jeremy is a roommate or a friend of his parents, he said, because people often see poly as swinging or polygamy. Same for the neighbors, at least until they get to know them better.

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They've learned the need for discretion. They said a family member reported them to Georgia's Division of Family and Children Services, alleging child abuse and prompting a weeks-long investigation. The Holders said it ended with no charges being laid and their daughter remaining in the home. Georgia's Division of Family and Children Services did not return multiple phone calls seeking comment.

But the experience also informed some of their desire to change public perceptions of polyamory.

So they march, and organize and raise their daughter the best they can. Their meetup groups continue to grow and they're looking forward bringing in new speakers to 2014's Atlanta Poly Weekend.

After all, the Holders and Mullins say it's not a choice -- polyamory is an inherent part of their sexuality.

"Life would probably be easier if I didn't feel the need to open myself up to loving more than one person," Jeremy said. "But it's part of who I am, and I feel that my life is enriched by it.

"It's up to us to figure out how to make it work."