A. 1) On July 24, 2006, the Plaintiff reported a marriage with Nonparty C on July 24, 2006, maintained the marriage relationship for one year and six months, while filing a divorce report on December 31, 2007, and has maintained a de facto marriage relationship until now. 2) The Plaintiff and C raise two minor children who were born in 2006 and 2012.

3) While the Defendant came to know that C was in a de facto marital relationship with C, he continued to commit an unlawful act against the Plaintiff. 4) Even though the Defendant promised to not meet C, the Defendant continued to make a promise to the Plaintiff, and continued to make a telephone call to C, even though he promised to not meet C.

[Reasons for Recognition] Evidence Nos. 1 to 12, Evidence No. 1 to 1, and the purport of the whole pleadings

B. Determination 1) The establishment of liability for damages has a duty to cooperate comprehensively with one another to maintain the marriage as a common life of the married couple. Therefore, if a third party, by committing an unlawful act with one of the married couple, thereby infringing on or impeding the maintenance of a common life of the married couple falling under the essence of marriage and infringing on the other spouse’s right as the other spouse, thereby causing mental suffering, such act constitutes a tort in principle (see, e.g., Supreme Court Decision 2013Meu2441, May 29, 2015). The same applies to a de facto marital couple who formed an substance of marital life but did not report only the marriage, but only constitutes a tort against the other spouse. According to the above acknowledged facts, it is reasonable to view that the defendant, as a result of the above recognition, violated the Plaintiff’s common life between the Plaintiff and C, or inflicted mental suffering on the Plaintiff by interfering with its maintenance. Therefore, the defendant is liable to compensate for damages arising therefrom.