Like Love, Robin Trask of Loveland, Colo., struggled with monogamous dating relationships in high school.
"My mother lived in Colorado and my father was in Texas, so I had a boyfriend in each place," Trask, the executive director of Loving More, told ABCNews.com.
"I felt wretched about myself," said Trask, 45. "I fell deeply in love with two people, and I had to choose."
Trask has three partners: the man she has lived with for four years; a man with whom she has been involved for 23 years who is married and lives outside the country; and a third man from New York City (he might be married; she doesn't know).
There are rules. The wife of her second partner forbids her husband to sleep with anyone but Trask.
Trask's sexual encounters are always one-on-one with a partner. But in a previous polyamorous marriage of 18 years, she had a threesome with her husband and his girlfriend.
"The dynamic was different, and it surprised me," said Trask, who identifies as heterosexual. "For me, it was about spirituality, much more about the relationship and emotional connection than just sex."
Trask likes the extended family that polyamory provides. She has three children -- 22, 18, 13 -- and her first husband's girlfriend also had children who spent holidays together.
"These are important relationships," she said. "The children grew up together."
Some polys support legalizing civil unions or incorporating their "clusters" as a corporation to gain health care and joint property rights. But Trask said her biggest concern is raising awareness so polys do not lose their children or jobs.
"We want it to be OK when you have two dads or two moms -- or whatever configuration -- at parent teacher conferences, and they don't freak out on you."
In polyamory, there are still are jealousies and pain, the same dynamics that can occur in a monogamous marriage, but the "full disclosure" between partners makes it more honest, according to Trask and Love.
Polys say that monogamy is a cultural norm that often fails. "As a result, many marriages are train wrecks, even when they don't end in divorce," said Love's husband, "Cougar," 58.
"Few people have good models to base their polyamory rules on," he told ABCNews.com. "For this reason, polyamory agreements must be negotiated with tenderness, empathy, partnership and the commitment to keep everyone safe."
Love and Cougar's goal is to create a "polyfidelitous family" -- four, five or six people who don't have relationships outside the marriage.
"Every person in a cluster or family realizes that no one can be completely happy if anyone is not," he said.
But Judy Kuriansky, a sex therapist and professor at Columbia University Teachers College, said being successful at polyamory is a tall order.
"[It] demands knowing yourself, replacing guilt with acceptance, communicating and embracing sexual energy, spirituality, new beliefs and a new culture," she told ABCNews.com. "Overcoming jealousy is key."
As a clinical psychologist, Kuriansky has seen some "dismal failures, even for the leading proponents."
"One wife left her poly husband, saying, 'I'm just a girl from Kansas. I finally realized I don't want my husband f**king other women.' A husband had a rude awakening when his wife added another man to their household and her bed, only to declare she wanted a sexual exclusivity with another man."