For 10 years after marriage she was very devoted.
In fact, when she heard stories about women cheating on their spouses, she would feel hatred for them and believed such a situation would never befall her.
But seven years after they married her husband, Duc Tien, went abroad to work after facing some sudden financial difficulty, and she began to feel empty, especially at night after her children went to asleep and her husband was hard at work with his cell phone turned off in a foreign country.
At the same time, at work, a male colleague – a married man – showered her with attention, and before she knew it her heart was lost.
Thuy says at first they just caught eyes as they left the factory after late shifts. Then they saw each other more as they often sat together during lunch, but with other colleagues. Finally, the two started to date.
"I always felt jumpy for fear of getting caught," Thuy recalls.
"A mere indifferent joke would make me think people were pointing at me."
At home, whenever she saw her children or spoke with her husband, she would feel ashamed. She tried to break up with her lover hundreds of times but failed. "It felt like addiction," she admits.
The denouement she had dreaded came when her lover’s wife showed up at their factory one day and made a scene in front of thousands of workers at rush hour.
"I wished I had died right then," Thuy laments.
Thuy’s husband soon got wind of the affair. The only thing he told her was to sign off on divorce papers though she begged for forgiveness.
Their children chose to live with him, afraid their friends would make fun of them for having an adulterous mother.
Her heartbroken parents fell seriously ill.
Thuy knows she can never be free of people whispering about her past and social stigma.
According to the Hanoi-based Institute for Family and Gender Studies, cheating is the second leading reason for marriage crises in Vietnam (25.9%) after only conflicting lifestyles (27.7%).
Psychologists say cheating used to be associated only with men, but recent studies have found both sexes are culpable.
Indeed, a survey by the American Journal of Marriage and Family found 74% of men and 68% percent of women saying they would cheat if they knew they would not get caught. Besides, asked if they have cheated at least once in their lives, 57% of married men and 54% of married women admitted to doing so.
In Vietnam, relationship expert Le Anh in the southeastern province of Dong Nai tells VnExpress that married men are likely to cheat if they have the opportunity even if their wives are as "attractive as beauty queens."
Married women often cheat when they run out of love or feel disappointed in their spouses. "However, there are people who remain faithful even when they no longer feel much love for their spouse because they have values and integrity and understand the consequences of cheating."
Nguyen Thi Minh, who has a Ph.D. in psychology and teaches at the HCMC National Academy of Public Administration, agrees with him, saying whatever the excuse, unfaithful people have only themselves to blame. Many people facing difficulties in their marriage and life do not cheat even when they have the opportunity to do so, she says.
According to these experts, unfaithful spouses usually feel happy and satisfied only for a short time. Most feel tormented, guilty and ashamed before their children, parents and society. They feel insecure because they know they are in the wrong even if their spouses treat them badly and give them an excuse for cheating.
Nguyen Manh Dung, 37, of HCMC, knows the pain of being a cheater as well as anyone else.
Three years ago he met his old flame at a high school reunion. She was divorced and courted him, even started a business in which they became partners to have more time together and strengthen their bonds.
Passionately in love with the woman, he divorced his wife.
Though he fell out of love with his wife, he still feels guilty about her and his son, and feels he owes her.
His parents and siblings have disowned him and disdained his new lover, and instead take good care of his ex-wife and son.
"A few friends of my ex-wife and mine avoid me," he says. "Since I divorced, I have not had a good night’s sleep."
Dung often dreams about returning to his old life, but knows when he wakes up that things can never be the same again, he says.
Experts say many people cheat because they think they have fallen out of love with their spouses, but realize they want to stay married when they are on the brink of a divorce or after the divorce.
Giving marriage a chance
After three years of marriage, Hong Anh, 27, of Hanoi filed for divorce and left her child to her husband, believing he did not deserve her.
She says: "He did not know how to please me, either in or out of bed. He worked at his computer all day long like a robot."
After her marriage ended, she flew to HCMC with a single man, who seemed caring, to start a new life. They had a child, but the romance ended and her husband now works hard to support the family while she has become unemployed. But unlike her first husband, he does not work quietly and instead constantly insults her for living off him.
During such moments, she cries, not out of humiliation or sadness, but regret. She realizes it was not that her former husband did not love her; he was just too busy earning the family’s a livelihood.
She remembers how she used to sigh and act irritably when she was unable to sleep because he was hard at work at midnight.
"I feel tormented and realize I miss him and my child."
According to relationship expert Le Anh, Anh did not "give marriage a chance" but let her selfishness and ideas about love dominate.
"Spouses should spend at least three months to find a way to fix their marriage when it is in crisis.
"During those three months, they should separate physically and emotionally to get perspective and see where each has been wrong in order for them to change."
But if they fail, they should divorce without fanfare and look for new love instead of hastily rushing into an illicit affair.
Minh says people with high self-esteem who own their thoughts and feelings are less likely to cheat than insecure ones who can be easily influenced by others.
"Thinking about the consequences is also a way to avoid cheating."
A 2017 study published in the English Journal of Sex Research listed four leading reasons that kept people from cheating: moral values, fear of consequences on children, fear of having to live alone, and fear of consequences on lovers.
Thuy’s ex-husband has remarried and had new kids, but her own children still do not want to return to her.
As for Manh Dung, the price of being reunited with an old love will always feel too high.
*The names of people interviewed have been changed to protect their privacy.