Two-person marriage, be it gay or straight, is still such the norm that even the most progressive among us do a double-take when someone says they like their relationships a little more populous. (This stigma is also why, with the exception of the Northern Virginia triad, all of the other polyamorous sources in this article asked to go either by their first names or pseudonyms).

Increasingly, polyamorous people—not to be confused with the prairie-dress-clad fundamentalist polygamists—are all around us. By some estimates, there are now roughly a half-million polyamorous relationships in the U.S., though underreporting is common. Some sex researchers put the number even higher, at 4 to 5 percent of all adults, or 10 to 12 million people. More often than not, they’re just office workers who find standard picket-fence partnerships dull. Or, like Sarah, they’re bisexuals trying to fulfill both halves of their sexual identities. Or they’re long-term couples who don’t happen to think sexual exclusivity is the key to intimacy.

Elisabeth Sheff, a sociologist who interviewed 40 polyamorous people over the course of several years for her recent book, The Polyamorists Next Door, says that polyamorous configurations with more than three people tend to be rarer and have more turnover. “Polys” are more likely to be liberal and educated, she said, and in the rare cases that they do practice religion, it’s usually paganism or Unitarian Universalism.