A. The Plaintiff and C completed the marriage report on December 1, 1991, and they were legally married couple, and they were divorced on December 7, 2015.

B. Around April 2015, the Defendant committed an illegal act with sexual intercourse, knowing that C was married.

[Ground of recognition] Unsatisfy, Gap evidence Nos. 1 through 4 (including additional number), the purport of the whole pleadings

2. The judged couple shall live together, and have the duty to support and cooperate with each other; and

(Article 826 of the Civil Act). Husband and wife, as a community in which mental, physical, or economic combination is achieved, shall have the duty to cooperate and protect each other in a comprehensive manner so that marriage as a marital community is maintained, and shall have the right to such a duty.

As such, as the content of the marital or marital life maintenance obligation, the married couple bears the sexual duty that should not commit any unlawful act.

If one side of the married couple commits an unlawful act, the other side of the married couple shall be liable for damages caused by a tort against the mental suffering which the spouse has sustained.

On the other hand, a third party shall not interfere with a married couple’s community life, which is the essence of the marriage, such as interfering with a couple’s community life by interfering with another person’s community life.

In principle, a third party's act of infringing on or interfering with a marital life falling under the essence of marriage by committing an unlawful act with either side of the married couple and causing mental pain to the spouse by infringing on the rights of the spouse as the spouse.

(See Supreme Court Decision 2013Meu2441 Decided May 29, 2015, etc.). According to the above acknowledged facts, the Defendant committed an unlawful act with a sexual intercourse with the knowledge that C is a married spouse, which infringes on or interferes with the common life of the married couple corresponding to the essence of marriage and infringes on the Plaintiff’s spouse’s right as the spouse, thereby suffering mental pain on the Plaintiff.