Cliff greets me at the door of his family's apartment in Tacoma, Washington, trying to contain an excited golden Labrador mix that has managed to wriggle between his legs. Behind him stands his wife, Britt, who offers a cheery hello, while their 3-year-old son, Gareth, sizes things up from a safe distance.

I pass the test. The blond toddler grabs my hand and leads me down the hallway into his immaculate bedroom, where he immediately begins pulling toys down from a shelf: toy trucks, interlinked train carriages, a rubber snake. On the wall hang pictures of rocket ships and distant planets, and in the corner float a bunch of helium balloons. Britt explains that Gareth just celebrated his birthday. "Happy day!" shouts Gareth, which is what he prefers to call it.

We migrate to the family room, and Britt, 24, offers me a drink as we sit chatting on their brown sectional sofa. Cliff, 29, occasionally interjects from the adjacent kitchen, where he, a former coastguardsman turned chef, is cooking a dinner of pulled pork. Gareth, a curious and tactile child, gives me an unsolicited hug, and his mother asks him to stop bothering me. We're discussing the family's recent move to the area from Sarasota, Florida. Out of the corner of my eye I notice Gareth sidle back up to me, a picture book in hand, which he slides into my lap.

"Gareth," groans Britt. "Dadave will read that to you when he gets home."

 (David Ryder/Vocativ)

"Dadave" is Dave, Gareth's other father. The four of them live together in a cozy two-bedroom apartment that overlooks a large reserve, 40 miles south of Seattle. In many ways they are a traditional family: Cliff and Dave both work, and Britt spends her days looking after Gareth. All three adults settle on the couch at night to watch TV once their son has gone to bed.

"It is very normal, except for the fact that we have one more adult living in our household," says Britt. "The only real difference is that we're buying food for one more person, and that person sleeps in our bed."

Britt, Cliff and Dave are polyamorists, which is to say they are interested in romantic relationships with more than one person. Specifically, they are a triad, meaning they are involved with one another both emotionally and sexually. V formations, which are also common to polyamory, involve one person who has a relationship with two others who don't connect; quads are usually couples that come together, though not all parties will engage. But these formations are just frameworks people use to describe their situations — there are no rules to, and seemingly endless permutations of, poly.

Without census information or other quantitative data, the exact number of polyamorous families is hard to pin down, though polyamory nonprofit Loving More estimates there are between 1 million and 1.5 million individuals in the U.S. who identify as poly. (A recent article by Scientific American states that between 4 percent and 5 percent of the U.S. population practices consensual non-monogamy, which includes polyamory.)

A working definition of polyamory is almost as elusive. The etymology of the word offers the cleanest explanation: Rooted in Greek (poly = many) and Latin (amor = love), it means, essentially, many loves. How this plays out in real life is more complex. Britt explains that people in polyamorous relationships are sometimes confused for swingers (couples who trade partners for a night of non-monogamous pleasure), which is not only reductive but also a little too glamorous a reference for the humdrum, everyday experiences of most poly families. More often, polyamory is lumped in with polygyny or polyandry, which refer to a man or a woman, respectively, who have multiple wives or husbands — a setup that usually shares a close connection with religion.

Britt is quick to point out that no one situation, her own family unit included, is representative of polyamory as a whole. "Poly is a build-your-own relationship structure. Your mileage will vary depending on what the person involved is doing," she explains. "All that really matters is that everyone is ethically treated. As long as everyone is on the same page, it can be whatever you want it to be."

For them, it began with Britt and Cliff. The two met in 2008 at the Fandemonium sci-fi convention in Idaho. Britt broke up with her then-boyfriend during the conference, and Cliff asked her out to lunch a week later. They hit it off and things soon became serious and, at that stage, monogamous.

To hear them tell it, their polyness, as it were, happened organically. They had been dating for a couple of years before the subject came up, and even then, it was tangential. "Shortly before we got married, Cliff admitted to me that he had some desires toward the same sex," says Britt. "It didn't bother me because I've always been open about my bisexuality. I said, 'Do you want to try to do something about that? Because I'd hate for you to feel unfulfilled and like you don't have any kind of freedom in our marriage.' And he was, like, 'Yeah, we'll see what happens.'"

It was another year before he did anything about it. By now the pair was living in Florida, and Cliff placed an ad on Craigslist looking for players interested in joining them for weekly Dungeons & Dragons games. A few people responded, and Dave was one of them. He'd come by each week, arriving earlier than the others and staying back after everyone else had left. One day, Britt confided in Cliff that she found Dave attractive, and he told her he felt the same.

They never explicitly discussed sleeping with their friend, but it became clear that Dave also found them attractive when movie nights led to heavy petting on the couch. Britt was the first to sleep with Dave, but Cliff wasn't far behind. They soon became an established threesome, in and out of the bedroom.

"We talked to Dave and said, 'We like you. We would like to date you. What do you think?'" says Cliff.

Dave was into it. Though this would be his first time in a triad, it wasn't his first time in a polyamorous relationship. His first serious girlfriend had been involved with another guy when he met her, and though the boyfriend wanted no part in it personally, he gave the two his blessing.

So the three of them started going out together, having dinners at home and doing other typical dating activities. Dave slept over at Britt and Cliff's so often he ended up moving in, but he had his own room and was still openly seeing other people. "It was such a natural progression," says Cliff. "It's like, So we're pretty much doing this now."

 (David Ryder/Vocativ)

The three of them coasted happily along for the next couple of months — until Britt got pregnant. Though he stayed with them throughout the pregnancy, Dave broke things off and moved to Ohio shortly after Gareth's birth. He was only 20 at the time and openly acknowledged that he "wasn't mature enough to do the whole family thing." It was only after he left that Britt and Cliff realized the true extent of their feelings. "It was unpleasant," says Britt of the separation.

They'd been apart for a year when Dave confided to them that he was struggling in Ohio and they persuaded him to fly back east. This time, however, things took on a certain urgency. Britt's mother was selling her house and moving to Washington and, tired of living in conservative Florida and looking for a change, Britt and Cliff decided to follow her. But when they asked Dave to join them, he wasn't convinced. It was in the early hours of Jan. 1, 2013, when the underlying tension of their undefined situation broke the surface.

"I came home, still half drunk, and told Britt that I wasn't going to be moving," says Dave. "She broke down in tears and we had a lengthy conversation. It boiled down to the fact that it felt like I was breaking up with her, that she didn't want that and that they'd never be coming back to Florida. It was at that point I let my feelings be known and admitted that I didn't think her or Cliff felt that way.

"In hindsight I was pretty blind, because I thought it was all casual fun with friends and apparently I was wrong," he continues. "The romance didn't really start showing until after we had that talk on New Year's Day, and from there it grew. At first, I was mostly only interested in Britt romantically and Cliff sexually. Once we moved, I really started to love both of them in the same way."

By March of that year, the three of them and Gareth were living in Tacoma, and everyone agrees that the relocation marked the official beginning of their poly family. This time around, for example, Dave didn't have his own room.

Walking along the street in downtown Seattle, Britt and Cliff are holding hands, and Gareth is hanging onto his mom. He reaches out to grab my hand, and we end up four in a row during the lunchtime rush hour. A couple of passersby smile at us even though we are taking up the vast majority of the sidewalk.

"It's easier to just be a person, frankly," Britt says later, when I ask her about the difference between life in Washington versus what she experienced in Florida. "Florida is very draconian in many ways. I don't feel like I have to be afraid out here, so that's nice."

Britt's response is not necessarily hyperbole. Because of ignorance or outright discrimination, some people just seem to react negatively to poly folk. Their three-way relationship has caused demonstrable friction for Dave and Cliff: Dave lost friends who didn't approve of the setup, and Cliff's polyness has caused more tension between him and his religious parents than his bisexuality did.

It's rare, but children have even been removed from the custody of polyamorous parents. Far beyond the mechanics of adult relationships, questions about parenting while poly form a constant, anxious thread on poly information forums and Reddit. It's certainly a cause of concern for Britt and her partners.

Britt, Cliff and Dave aren't 100 percent sure of Gareth's paternity. They think he might be Cliff's in a biological sense, but none of them sweat the details. "It truly doesn't matter who his genetic father is, because I am his father and so is Cliff, and I will continue to be his father for the rest of his life," says Dave.

What does worry them, however, is how their precarious legal status might come into play now that Gareth is nearing school age. Britt and Cliff are married, and while both would very much like to marry Dave — and vice versa — that's currently out of the question. They fear this could pose a problem when it comes to Dave picking Gareth up from school or signing hospital or other legal documents on his behalf.

Then there are the social repercussions. "I worry about potential friend situations," explains Britt. "You know, Gareth makes friends with somebody and then they come over here and they play with him once, and they go back to the family and say, 'You know, Gareth has two daddies and a mommy.' I worry a lot about that."

Gareth is understandably ignorant of the situation. "He's a little too young to understand the concepts," says Cliff. "But as he asks questions and things come up, we're going to explain it fully."

Britt adds that a subtle line of questioning has already begun. "He says to us, 'Two daddies?' Yeah, two daddies. And he knows that other kids don't always have two daddies," she says. "Sometimes he says, 'Two mummies?' And I say, 'No, only one mommy.' And he goes, 'Oh, OK.'"

The easy dismissal of rights for polyamorous families is a sore point for them all, especially Britt. She says she's been labeled a whore who can't commit to a regular relationship on more than one occasion, but that doesn't worry her as much as the lack of legal protections for her family.

Both she and Cliff describe being frustrated when the same-sex-marriage debate picked up steam on a national level. Though both are ardent supporters of marriage equality, they feel thrown under the bus when activists are quick to distance themselves from polyamory and the idea of plural marriage, which is often placed below homosexuality and above bestiality on the morality scale.

"They're trying to talk to people that are already hesitant to let two men or two women marry. So, they're like, 'At least we're not that,'" says Cliff. "They're taking what they can get within a law rather than trying to go for all of it. I can forgive them. But at the same time, it doesn't necessarily make it right."

He adds that there are pragmatic considerations as well: "I would like to have the benefits that married people have. Benefits apply to relationships when you get married that you don't have otherwise. I look at that and think, Why can't we?"

Things get a little murkier when we discuss religious polygamy. Britt posits that some of society's discomfort with plural relationships stems from the more nefarious forms of poly, which are often related to religions and cults. By this she means specific cases where young girls are indoctrinated and pushed into polygamous marriages. She's concerned that these women lack agency — and also that people assume her situation is the same.

It's clear that commenting on these divisions makes her uncomfortable, as if she's going against some kind of poly sisterhood, and she brings the conversation back to the public's general misgivings about polyamory. "They either think about the abusive religions or people who are just out to have a swinging good time. Which isn't the reality of it," she says. "I'm sure people picture sex parties and wild nights. We're in bed by 10:30. I'm tired. I get up at 7."

Not all conflict is external. As in any relationship, there is a certain amount of negotiating and compromising to be had. However, there are unique extra challenges faced by polyamorous families. Child care is an obvious example.

 (David Ryder/Vocativ)

Dave explains that the good outweighs the bad and that having another set of hands to take over when your partner needs a break, as well as an extra paycheck to cover childcare expenses, is not only good for the kid but for everyone's well-being. That said, two parents don't always agree on the best way to raise a child, and having a third perspective can exacerbate any conflict. Which is why they've chosen to resolve disagreements by committee. "There can be something we disagree on regarding raising him, but we work as a democracy, so if one person has an idea that the other two don't like, it's not implemented," Dave says.

The rules regarding each other's conduct are a little more fluid. All of us are seated around the dining room table, the plates having been cleared after a family meal. Gareth has long since gone to bed. We're discussing how one learns to function as part of a polyamorous unit. The word "negotiation" comes up a lot. So does "jealousy." "It's always talked about," says Cliff.

For them, it's come up a fair bit recently. They had been polyfidelitous (that is, only sleeping with one another) since moving to the West Coast, but in recent months Britt has struck up a romantic friendship with a new guy, and Dave has started dating another woman. This doesn't mean they're any less committed to each other, but it has caused problems for Cliff, problems they've since had to work through. Though not for the reasons one might expect. "I wasn't jealous of the fact that they're with somebody else — like, 'I don't want you to be with them, you're mine,'" Cliff explains. "It was, 'I'm jealous that you're with someone else. I want to have that happiness that you have, of having someone else.'"

Navigating sex and relationships is central to polyamory. Britt, however, bristles when I ask about their sex lives. It's an area, she says, that everyone is especially obsessed with: Who sleeps with whom, when and in what configuration? She and Dave won't be drawn into it. Cliff begins to open up, and Britt carefully monitors what he's saying. He tells me that sex comes down to communication. "We're all attracted to each other, we all have sex with each other — sometimes one-on-one, sometimes all together — we don't do anything weird," he explains, before Britt cuts him off.

It's clear that she wants to ensure it isn't all reduced to sexual mechanics. And rightly so. She mentions several times that she finds it odd that a reporter even wants to ask questions of her family, and I agree that stories like this, that veer into the territory of social anthropology, can add to the sense of otherness that often accompanies discussions of nontraditional relationships. I ask her what she'd like the takeaway to be, what she wants to tell people about polyamory.

"Expecting one person, or even two, to be anything and everything — that's a lot of needs to be fulfilled by just them. You can't expect somebody to be everything for you," she says, adding that for her, being poly is about letting more love into your life. "I use the word 'compersion': the feeling of happiness you get when someone you care about is receiving happiness from another. …I believe love grows exponentially the more that you have to give."

This article originally appeared at Vocativ.com: A poly family portrait: More love to give