Combining with a Divorce Lawsuit

If the divorce lawsuit and the lawsuit against the affair partner are joined, the same panel of judges examines the same facts at once. The spouse's and the affair partner's liability are judged on the same evidence, which lowers the risk of conflicting conclusions, and witness examinations and fact inquiries can be done once.

On the other hand, a divorce case also involves division of property and child custody, so it tends to take longer. If you want to resolve the affair partner issue first, or haven't decided yet whether to divorce, you can file the lawsuit against the affair partner in a civil court first. If your evidence is thin, we also consider pursuing the divorce first and using material obtained in that process.

The Supreme Court has held that when a compensation claim (위자료) against the spouse is dismissed because both spouses are equally responsible for the breakdown of the marriage, a third party who took part in the infidelity cannot be held liable for damages on the ground of the divorce either (Supreme Court Decision 2023므16678, rendered June 27, 2024). The reason is that divorce compensation is liability for the breakdown of the marriage, not for an individual act of infidelity (부정행위).

So when claiming against the affair partner together with a divorce, you must be prepared for your spouse to file a counterclaim (반소) alleging your own faults. If there are circumstances on your side that could be disputed, we carefully decide first what kind of harm the claim should be framed around.

If the affair began before the divorce lawsuit, we additionally submit the fact that the two kept meeting during the lawsuit so it is reflected in the compensation. This can be viewed as continuing the relationship despite knowing it was wrong.

It is different when your spouse began seeing someone new during the divorce lawsuit. If the marriage had already broken down beyond repair by then, that relationship is not a tort. However, it is not unusual for the relationship to have actually started before the lawsuit, so finding evidence of when the two first made contact is important.

Many people decide to divorce while suing the affair partner as a married plaintiff. Filing a divorce lawsuit does not automatically move the pending lawsuit against the affair partner to the family court. To be compensated for the harm of the divorce as well, you must apply to change the cause of action in the existing lawsuit, and if the court regards it as a family case, it transfers the case to the family court (Supreme Court Decision 2024므12628, rendered July 16, 2026). When changed this way, the existing claim is as a rule treated as replaced by the new claim, and even if the change is made on appeal, the case does not start over from the first instance; a collegiate panel of the family court continues hearing it as the appellate court.

Changing the cause of action means you must newly prove the link between the affair partner's infidelity and the breakdown of the marriage. If the main cause of the divorce was financial problems or other conflicts, the amount may not increase as much as you expect, so we first assess whether the change is worthwhile.

If you say in the divorce lawsuit that you found out about the affair recently and in the affair lawsuit that you have known for a year, both statements lose credibility. The date you learned of the affair is also tied to the starting point of the time limit, so once set, that date must stay the same in both cases.

Compensation from your spouse and from the affair partner is for the same harm, so an amount received from one side can affect the decision on the other. We first set the overall amount and then work out together how to claim it from each party.