In adultery lawsuits, the most common defense raised by the third-party defendant is this: by the time they met, the plaintiff and her husband (or his wife) were already estranged, so their affair was not the cause of the marriage breakdown. The two questions I most often hear in consultations are these. Will mere separation make this defense work? Can the plaintiff still recover damages while separated? This article uses the Uijeongbu District Court ruling 2023deudan5206 to organize how this defense is treated.
Basic structure of the case
The plaintiff (wife) sued her husband's affair partner (defendant) for damages. The defendant admitted to the affair itself but argued that by the time the relationship began, the marriage between plaintiff and her husband had already broken down.
The defendant relied on:
- The plaintiff had already taken her children and left the home due to the husband's domestic violence and use of paid sex services, and they were separated.
- Therefore, when the defendant began the relationship with the husband, the couple was effectively split.
- The affair was thus not the cause of the breakdown but only a consequence of an already-broken relationship.
The core issue is straightforward: in a case where other grounds for breakdown such as separation and domestic violence exist alongside the affair, can the third party's adultery still be recognized as a cause of the breakdown?
The court's conclusion: the defense was rejected
The Uijeongbu District Court did not accept the already-broken marriage defense. The decisive ground was the final judgment in the divorce action the plaintiff had earlier filed against her husband.
In that prior divorce action, the court found:
- Not only the husband's domestic violence and unjust treatment (Civil Act Article 840 subsections 3 and 6), but also the affair with the defendant (Article 840 subsection 1), were causes of the marriage breakdown.
- The husband had made the same argument that the plaintiff abandoned the home and the marriage had already broken down, but the court rejected it for lack of evidence.
In the present adultery case the Uijeongbu court applied the binding effect of the prior divorce judgment's factual findings and held that the defendant's affair was one of the causes of the breakdown. The affair was not the sole cause, but having been one of the causes, the defendant was liable for damages for plaintiff's emotional injury.
Damages assessment: 10 million KRW awarded out of 30 million KRW claimed
In setting the damages amount, the court considered that the husband's domestic violence and other fault factors combined with the affair to bring about the breakdown. The result was an award of 10 million KRW out of the 30 million KRW claimed.
| Item | Finding |
|---|---|
| Defendant's liability | Recognized (affair was one cause of breakdown) |
| Damages claimed | 30 million KRW |
| Damages awarded | 10 million KRW |
| Reason for reduction | Combined effect of husband's domestic violence and other fault factors |
When other breakdown causes are recognized alongside the affair, the damages award tends to be lower than in a typical case.
Why the already-broken marriage defense rarely succeeds
In my consultations, third-party defendants raise this defense very often. But courts accept it only in limited cases, for the following reasons:
- The timing of the breakdown is hard to prove. Mere separation does not legally mean the marriage has broken down. The couple may still be working on reconciliation, or be temporarily apart for childcare reasons, among many other situations.
- Factual findings in the prior divorce case carry directly into the adultery case. When, as here, the prior divorce judgment found the affair to be one cause of the breakdown, it is very difficult to overturn that in the adultery case.
- It is hard to escape the assessment that the affair itself contributed to the breakdown. Even during separation, one spouse's affair effectively shuts down the possibility of reconciliation, and the court does not overlook this.
The logic that separation automatically equals breakdown is not accepted by the courts. The legal meaning of breakdown is not decided by separation alone; the possibility of reconciliation and any efforts toward it are evaluated alongside.
What the plaintiff should prepare
For a plaintiff filing an adultery suit, the key is to assemble materials that will neutralize the defendant's already-broken marriage defense in advance.
- The prior divorce judgment and its course: If the affair was recognized as one cause of breakdown in the divorce case, that becomes a very strong basis in the follow-up adultery case.
- Evidence of reconciliation efforts during separation: KakaoTalk messages, records of childcare discussions, attendance at family events—daily traces that show separation alone cannot establish breakdown.
- Objective evidence of when the affair started in earnest: Communication records, messages, photos, evidence of joint outings. If you can show the affair began not immediately after separation but at a time when reconciliation was still possible, you weaken the defense.
When I take on an adultery case, I review the linkage with the prior divorce case first, because the weight of the factual findings changes greatly depending on the order in which the two cases proceed.
How the defense can still be meaningful for the defendant
For a defendant raising this defense, mere separation will rarely exempt them from damages. But the following materials can meaningfully reduce the amount:
- Objective evidence that, before the affair began, the marriage was effectively beyond recovery (long-term separation, divorce agreement, practical settlement of child custody and asset division).
- Evidence of other breakdown causes (domestic violence, paid sex services, gambling, etc.).
In this case, the defendant's liability was still recognized, but the combined effect of other breakdown causes operated as a reduction factor. The defense does not fully eliminate liability, but it can meaningfully cut the award.
Frequently asked questions
Q. If I met him while he was separated, can I avoid all damages? A. Separation alone does not eliminate damages. The fact of separation and the legal fact of marriage breakdown are different. The court evaluates the reasons for separation, the chance of reconciliation, and how much the affair contributed to the breakdown.
Q. Can I file the adultery suit without first filing for divorce? A. Yes. But as in this case, when a prior divorce judgment exists, its factual findings carry over, so it is often better to plan the order and strategy of both lawsuits together.
Q. How much is the adultery damages reduced when other breakdown causes are present? A. It varies. In this case 10 million KRW was awarded out of a 30 million KRW claim, a substantial reduction. The reduction depends on the weight of other causes and how much the affair contributed.
In closing
The already-broken marriage defense, the standard line in adultery lawsuits, is generally not accepted on the basis of separation alone. As in this Uijeongbu District Court case, when the prior divorce judgment has already found the affair to be one cause of breakdown, the defendant will be held liable in the adultery suit. Where other breakdown causes are also present, the defense can operate to reduce the damages amount. Because outcomes vary widely with the facts and evidence, organizing the facts and evidence before filing is critical.
Written by Jonjae Law Firm, Family and Inheritance Team · Last reviewed 2026-05-30
This article is general legal information based on Uijeongbu District Court ruling 2023deudan5206, and does not guarantee the outcome of any individual case. Outcomes vary with the facts and evidence, so please consult an attorney separately for any specific matter.
