"The woman hissed, 'I bet you wonder where your husband is. He's with me,'" Shorn, the author of Leave a Cheater, Gain a Life: The Chump Lady's Survival Guide, recalled the voice on the other end of the line telling her.
As the other woman relayed more details about the affair ― even boasting of having broken up the man's earlier marriage ― Schorn struggled to take it all in.
"Then, I told the woman on the phone, 'Oh my God, I hope I'm not pregnant.' After hearing that, she burst into tears. It was surreal, to say the least," Schorn told HuffPost.
Before ending the conversation, Schorn thanked the other woman for making the call.
"She was a toxic person but I'm still grateful she told me, even if her motivations were not pure," the writer said. "It took me a while to act on the knowledge but I left him."
Schorn's experience highlights an ethical conundrum for people who have had affairs with men and women in long-term relationships: Do you tell their primary partner? Is it your story to tell or is the impetus to come clean all on the spouse?
Before making the call, it's important to consider if the affair was a one-time encounter or an ongoing, deeply involved relationship, said Megan Fleming, a psychologist and sex therapist in New York City.
"If the affairs are in the past and the other person is committed to their marriage, I would counsel not to disclose," she said. "Holding onto that secret is painful but as I see it, it might very well destroy a relationship the couple had already gone on to rebuild if you dump the info onto the spouse's lap."
Writer and one-time mistress Kate Rose was faced with this dilemma years ago. At the time, she had the full support of her lover to do whatever she felt was right. Ultimately, she kept it to herself.
"We had been together for two years and for me, I didn't want to make someone else's choices for them," she told HuffPost. "I didn't want to force my lover's hand or betray the trust that we had built. I left the telling up to him. After all, it was his relationship that was affected. I thought it was his choice to be honest, not mine."
"Unfortunately, such disclosures seldom yield such satisfaction and may backfire." Alicia H. Clark, a psychologist in Washington, D.C.
It's important for the other man or woman to consider their motives for disclosing the affair, stressed Alicia H. Clark, a psychologist in Washington, D.C. Sometimes, after being spurned or pushed away, affair partners want to strike back or regain power by revealing the relationship. It rarely works in their favor, she said.
"You may want to speak up to punish your lover for staying with their partner, or seek some level of legitimacy for a relationship that has lived too long in the shadows or dismissed," she said. "Unfortunately, such disclosures seldom yield such satisfaction and may backfire."
Sometimes, the desire to disclose truly comes from a place of goodwill, Fleming said. That may be the motive if the affair was short-lived or the affair partner had no idea their lover was in a monogamous relationship.
"With one of my married clients, the husband had met women on Twitter and started ongoing sexting conversations until one of these women reached out to his wife," Fleming said. "The woman had said in an email: 'I thought you'd want to know, as I would want to know.'"
The revelation upended the couple's marriage ― then, it made it stronger.
"It was a crisis in their marriage but I always say the crisis is the opportunity," Fleming said. "It was an opportunity to have the conversations they weren't having and to explore what needs and desires were not being met for both of them."
Today, Fleming said the couple is newly recommitted to their marriage and growing as partners.
"The disclosure actually ended up being helpful," she said.
Schorn, who started her blog Chump Lady after eventually leaving her unfaithful husband, said she almost always advises the affair partners to come clean.
"Unless you truly didn't know they were married, you were party to conspiring against this person," she said. "That's sexually humiliating. They did not consent to be cheated on. The least you can do is return a little of their dignity and tell the truth. Take your lumps, and then exit."
Rose, the former mistress mentioned earlier, thinks that no one affair is the same and that no one piece of advice could benefit those in such situations. Still, Rose advises affair partners to carefully consider their intentions in telling the spouse. It won't end well if you're hoping to end your partner's marriage and gain a fresh start for your relationship.
"If you're in a situation where you're the other man or woman and think that your partner will come running if you tell their significant other, you are sadly mistaken," she said. "Love doesn't work that way."