Husband secretly registers marriage with ex-lover

Ms. B.N. T (in Ha Tinh) asked: "My husband and I have been married for 5 years and have 1 son. My husband is 8 years older than me. We met when working on the same project, loved each other for nearly 2 years before holding a wedding.

Before coming to me, my husband had a university romance. We were in love for 4 years but for some unknown reason we broke up after graduating.

Because it was a matter of the past, having broken up a long time ago, I never asked him about my ex-lover. But I know that after breaking up with my first love, it was only 8 years later that he came to me. He is a gentle person, always taking care of his family. Since marrying me, he has always been thoughtful to his wife's family, so my parents and older brother are very satisfied with this son-in-law.

I thought family life would always be peaceful like that. But about 1 year ago, I saw many changes in my husband. He often goes on long business trips. When he gets home, he neglects his children, no longer spends time playing with them. Husband and wife no longer have weekends going for coffee together or taking each other for breakfast like before.

In the beginning, I just thought it was because of a lot of work, stress, because he was in charge of a rather important project. However, many times I saw my husband go to the restroom to answer someone's phone for a long time. Even about marital life, he also tried to evade.

Suspicious, I hired a detective to monitor and discovered a truth. More than 1 year ago, at a class meeting to celebrate the 15th anniversary of university graduation, my husband met his ex-girlfriend again. She is still unmarried and working in Da Nang. Old love meets again, inevitable feelings arise.

The noteworthy thing is that my husband did not tell her that he was married. 9 months ago, I don't know how my husband got a Certificate of Marital Status that he had never been married. After that, my husband went to register his marriage with his ex-girlfriend in her hometown.

Through what the investigators provided, I learned that the long business trips were actually my husband going to Da Nang to live with this new wife. Currently, she is pregnant. Really, knowing this news, I was very devastated and confused. I half wanted to divorce my unfaithful husband, half wanted to keep a complete family for my child. Lawyer, please ask, is my husband's marriage to his ex-girlfriend an illegal marriage? If it is illegal, how will it be handled? I would like to get advice.

Legal issues you are asking - lawyer Duong Thu Hien - Thanh Lam Law Company Limited advises as follows:

According to Clause 6, Article 3 of the 2014 Law on Marriage and Family (amended and supplemented in 2025), the marriage between your husband and his ex-lover is illegal marriage.

Clause 6, Article 3 stipulates: Illegal marriage is when a man or woman has registered their marriage at a competent state agency but one party or both parties violate the marriage conditions as prescribed.

Point c, Clause 2, Article 5 of the 2014 Law on Marriage and Family (amended and supplemented in 2025) stipulates the following prohibited acts in marriage: "A person who is married or cohabiting as husband and wife with another person or who is not married or cohabiting as husband and wife with a person who is married or cohabiting as husband and wife;".

Accordingly, the law prohibits wives and husbands from marrying or living as husband and wife with others or without wives or husbands from marrying or living as husband and wife with wives and husbands.

Comparing the above regulations, your husband, who is married, marrying his ex-lover is a violation of the law. This act is administratively sanctioned. Specifically, a fine of between 3,000 VND and 5,000 VND according to point a, clause 1, Article 59 of Decree No. 82/2020/ND-CP dated July 15, 2020 of the Government (amended and supplemented by Decree No. 117/2024/ND-CP):

“1. A fine of between VND 3,000,000 and VND 5,000 shall be imposed for one of the following acts:

a) Being married or having a husband but marrying another person, not having a wife or not having a husband but marrying someone you clearly know is married or has a wife;”.

Even, from May 18, 2026, people who are married and register to marry another person will be fined from 5,000 VND to 10,000 VND according to point a, clause 1, Article 62 of Decree No. 109/2026/ND-CP dated April 1, 2026 (effective from May 18, 2026.

In your case, you have the right to request the Court to annul your husband's illegal marriage to his ex-lover as stipulated in Point a, Clause 2, Article 10 of the Law on Marriage and Family in 2014.

In case the Court issues a decision to annul the illegal marriage between your husband and his ex-lover, the two parties must terminate the relationship as husband and wife. However, your husband's ex-lover is pregnant, so the child born is resolved according to the provisions of Clause 2, Article 12 of the Law on Marriage and Family in 2014. Specifically: "The rights and obligations of father, mother, and child are resolved according to the regulations on the rights and obligations of father, mother, and child upon divorce".

After her husband's ex-lover gives birth, her husband has the right to recognize the child as a child. At the same time, her husband has the right and obligation to look after, care for, raise, educate the child and fulfill the obligation to provide alimony for the child.

The above is the advice of the lawyer, hoping that she will soon solve her problems.