What it takes for ‘I didn't know he was married’ to be accepted

The thing we hear most often from people who have received a complaint as an affair partner is that they did not know. They say they were never told the person was married and that the person seemed to live alone. This argument has legal significance too, because the affair partner's liability is liability in tort, and a tort requires intent or negligence (Article 750 of the Civil Act).

The burden of proof is on the plaintiff to begin with

Case law does not go so far as to impose a duty to check whether a romantic partner has a spouse. So it is the plaintiff bringing the claim who must prove that the affair partner knew, or could have known, of the marriage. On this point alone, it may seem the defendant can simply sit back.

Negligence is examined as well. Even if you did not actually know, liability may be found if there were circumstances from which you could have known with a little care. This is why, between people who worked together on the same team for several years, a claim of not knowing about the marriage is not easily accepted.

Actual trials do not unfold that way. The plaintiff picks out parts of the two people's conversations that mention children or a spouse, and puts forward the fact that they were at the same workplace or in the same group. If the defendant cannot then present specific circumstances to the contrary, the court tends to lean toward the plaintiff's circumstantial evidence. Proof may be the plaintiff's burden, but in the end it is the defendant who must persuade.

The three things the court asks

When examining a claim of not knowing, the court generally seeks to confirm three things: what words and actions deceived you, when you learned of the marriage, and how you acted after finding out. If you have the following materials, set them aside and keep them safe now.

• Messages in which the other person introduced themselves as single or divorced, and conversations in which you asked whether they were married
• Circumstances showing they lived like a single person, such as meeting freely on weekends and holidays and having you visit their home
• The date you found out about the marriage and how it happened
• Messages right after that in which you cut off contact or protested

The third question is especially important. If the meetings continued after you found out, liability may be found for the period after that. If you set out the period when you did not know separately from the period when you did, you may not be able to dispute liability entirely, but you can narrow its scope.

Arguments that can backfire

Insisting you did not know when the circumstances from which you could have known are obvious is risky. If a photo with a wedding ring was on the person's profile, or your conversations frequently mention their child's after-school classes, the court will find it hard to believe that argument. Once one argument collapses, the rest lose credibility too.

In such cases, some cases are better served by admitting what should be admitted and putting the weight on the short length of the relationship and the fact that you ended it as soon as it was discovered. Which path to take is decided by looking at the plaintiff's evidence together with the conversations you have. If the other person ever showed you documents claiming to be divorced, be sure to keep those photos or conversations. Also avoid contacting the plaintiff or the other spouse directly to explain yourself after receiving the complaint. Things said in an emotional phone call are sometimes used as an admission that you knew about the marriage.