In 1983, after 25 years of marriage and two children, Amity Buxton learned her husband's long-held secret -- he had "jilted" his gay lover to marry her. Her life was turned on its head.
"My moral compass was broken living someone else's lie," said Buxton, now 82 and founder of the Straight Spouse Network. "I didn't know what was true or false. I couldn't trust my own judgment ... My identity was shattered."
Buxton, who lives in California, said it was worse than finding out her husband was having an affair. "I could always compete with another woman," she said. "But this way, I didn't have the right equipment and was doomed from the beginning."
He left and they agreed he would tell the children, a daughter in high school and a son in college. It took years before her husband could tell his son he was gay.
"The children thought it was their fault," she said. "But couples who stay together for the sake of the children make them feel even more guilty -- I couldn't stand the idea of secrets," she said.
Today, an estimated 25,000 heterosexual husbands and wives and 3.5 million children are too often the neglected parties when a gay spouse comes out of the closet, according to the Devote Campaign, which works for marriage equality for lesbians, gay, bisexual and transgender Americans.
Buxton turned her experience into advocacy when there were no resources available to those left behind, in pain and often victims of homophobia. The Straight Spouse Network just celebrated its 25th year.
"We are in the invisible minority," said Buxton, who was an educator in multiethnic schools. "No one pays attention to us."
Only about 15 percent of those spouses choose to stay in the marriage, according to Parents, Family and Friends of Lesbians and Gays (PFLAG).
Just last month, New York City author Jane Isay wrote an essay, "Keeping Marital Secrets Closeted" about learning her psychoanalyst husband was gay 15 years into their marriage in 1965. The couple decided to keep his coming out from their two sons -- aged 10 and 14 -- and stayed in the marriage "for the sake of the children."
Now 72, Isay looks back on that decision with mixed feelings. "When they finally learned the truth, our sons were more disturbed by our deception than by the facts," she wrote in the New York Times. "Our reasons didn't seem to matter anymore. Truth trumps lies, every time."
She said she also "paid a price for my silence" with her closest friends. "When I felt so alone, I could always remind myself what a good person I was being, sacrificing for the children."
She first noticed changes when her husband behaved "like a fugitive at the dining room table," she told ABCNews.com. Fearing she would lose him, she asked directly what was going on.
"Things hit me like ton of bricks," according to Isay, but they decided to carry on their marriage. "We did fine, we really did."
Soon after, her husband found "Gordon," and Isay heroically allowed him to go out with his lover two nights a week and on two vacations a year.
After their divorce in 1989, she fell in love again and had a 22-year marriage. But it was in his death from cancer that she learned the importance of the truth.
"It was amazing," said Isay. "What I learned from Jonathan was if you face the truth, you have power over it."
Her sons, now 41 and 46, have long forgiven their parents and are thriving with their own families, she said.
"I look at [my sons], and what did I do wrong?" asked Isay, author of "Walking on Eggshells" who is now writing a book about marital secrets. "They married the loves of their lives, I have beautiful grandchildren and it turned out okay. Better than okay."