Hugh McIntyre, a 26-year-old music writer, and Toph Allen, a 28-year-old epidemiologist, are in love and have an “amazing” relationship of two and a half years. One of the keys to their success: sleeping with other people.

“We wouldn’t change a thing,” says Allen, who lives in New York City with McIntyre. “We get to fulfill our desire of having sex with other people. We avoid cheating and the resentment that comes in monogamous relationships when you can’t pursue sexual urges.” Their relationship is not unusual among gay men. In 2005, a study found that more than 40% of gay men had an agreement that sex outside the relationship was permissible, while less than 5% of heterosexual and lesbian couples reported the same.

McIntyre and Allen say the strength of their bond is built on clear and open communication. And while that assertion will be perplexing or even taboo to many monogamous couples, a new study into gay couples in open relationships suggests that this skepticism is unjustified. In fact, the study says, non-monogamous couples can actually be closer than their more faithful counterparts.

In June 2015, Christopher Stults, a researcher at the Center for Health, Identity, Behavior, and Prevention Studies at New York University, launched a qualitative study of 10 gay couples in open relationships. He conducted 45-minute, individual interviews with each of these men and their partners, who ranged in age from 19 to 43.

The study, funded by the Rural Center for Aids/STD Prevention at Indiana University, had multiple aims. “We wanted to see how these relationships form and evolve over time, and examine the perceived relationship quality, relationship satisfaction, and potential risk for HIV/STI infection,” says Stults, who finished coding the interviews this week at NYU and hopes to have the study published early next year.

So far, Stults says his finding is that non-monogamous relationships can lead to a happier, more fulfilling relationship. “My impression so far is that they don’t seem less satisfied, and it may even be that their communication is better than among monogamous couples because they’ve had to negotiate specific details,” Stults says.

And open relationships “don’t seem to put gay men at disproportionate risk for HIV and other STDs,” Stults says. “To my knowledge, no one contracted HIV and only one couple contracted an STD.”

But despite Stults’s findings, there’s stigma associated with these kinds of relationships. In 2012, four studies from the University of Michigan found that participants’ perception of monogamous relationships were “overwhelmingly more favorable” than of open relationships.

“Gay men have always engaged more often in consensual non-monogamous relationships, and society has consistently stigmatized their decision to do so,” says Michael Bronski, a professor in the department of women, gender and sexuality at Harvard.

McIntyre and Allen say they’ve experienced the stigma themselves but that an open relationship is the most honest way for them to be together. “We’ve run into gay and straight people who have assumed our relationship is ‘lesser than’ because we’re not monogamous. I think that’s offensive and ridiculous,” McIntyre says.

So what makes an open relationship work? Participants in Stults’ study emphasized that success is predicated on creating rules and sticking to them. For McIntyre and Allen, two rules are key: “Always tell the other person when you hook up with someone else, and always practice safe sex,” Allen says.

For David Sotomayor, a 46-year-old financial planner from New York, sticking to specific rules is fundamental to the success of his open marriage. “They’re built to protect the love of our relationship,” he says. “We can physically touch another man and have oral sex, but we can’t kiss, have anal sex, or go on dates with other guys. We attach an emotional value to kissing – it’s special and unique.”

But sticking to the rules isn’t always easy. Sotomayor has broken them multiple times, which has caused conflict. “It creates a sense of doubt of whether someone is telling the truth,” he says.

Brian Norton, a psychotherapist who specializes in gay couples and an adjunct professor at Columbia University’s department of counseling and clinical psychology, says: “Sex is an emotional experience. There is emotion at play, and even in the most transactional experience someone can get attached.”

Norton believes that going outside the relationship for sex can lead to emotional insecurity. “I think it is a difficult pill to swallow that we cannot be all things to our partners,” he says. “A relationship is a constant balancing act between two conflicting human needs: autonomy and the need for closeness.”

Allen says: “It’s true that love and sex are intertwined, but they aren’t the same thing. Love is about so much more than sex. [There’s] intimacy, friendship, mutual care and respect.”

That gay couples are leading the way in sexually progressive relationships shouldn’t be surprising, according to Bronski. “Because they’ve been excluded from traditional notions of sexual behavior, they’ve had to be trendsetters and forge their own relationship norms,” he says.

Norton believes the facility with which gay men engage in open relationships may be related to a fear of intimacy. “The experience of coming to terms with your homosexual identity can often be associated with emotional abandonment, shame and rejection,” he says.

“So our experience with love and intimacy at an early age is often broken and compromised, so when someone tries to get close to us as an adult, defenses go up,” he says. “It’s human nature to avoid revisiting feelings of abandonment, and open relationships may be a way of keeping a distance between another man.”

But Allen says that being open has strengthened his relationship with McIntyre and brought the couple closer together. “I feel a greater sense of connectedness with Hugh because I get to see him explore his sexuality with other people and I feel gratitude to him for giving me the same leeway,” he says.

All the experts in this story say they believe open relationships can work when they are built on honesty and communication.