Adultery during marriage is one of the main reasons for the breakdown of marriage and the most common fault situation in divorce litigation. Many parties believe that infidelity is only a moral issue and cannot be pursued legally; some also think that if one party commits adultery, they can be made to leave the marriage with nothing and claim a large sum of money.

These two cognitions both have biases, and the boundaries need to be clarified in accordance with the provisions of the law. Article   1091   of the Civil Code stipulates: If any of the following circumstances lead to divorce, the innocent party has the right to claim compensation for damages: (1) bigamy; (2) cohabitation with another person; (3) the practice of domestic violence; (4) mistreatment and abandonment of family members; (5) other major faults. Compared with the original Marriage Law, the Civil Code has added the catch-all clause " “other major faults”  ", which is of key significance.

Under the framework of the original "Marriage Law," only when the severity reaches bigamy or cohabitation with others can a claim for compensation for damages be made, and occasional extramarital affairs are difficult to gain support. After the implementation of the "Civil Code," serious acts of infidelity within marriage can be included in the category of  “other major faults”  , and if the innocent party asserts compensation for mental damage based on this, the court may support it. This is a strengthening of legislative protection for the obligation of fidelity between spouses.

 However, not all affairs can result in compensation, and the court will comprehensively judge whether the affair constitutes  “major fault” from the following aspects: First, the duration and severity of the affair; long-term, repeated affairs, or maintaining stable and improper relationships with others, are more likely to be deemed as major fault; second, the timing of the affair; for example, having an affair during the woman's pregnancy or breastfeeding period, the degree of fault is more severe; third, the mental damage consequences caused to the innocent party; fourth, whether there are other acts of fault such as transferring property.

 Regarding the compensation amount, in judicial practice, it is usually in the range of several thousand to several tens of thousands of yuan, and the judgment amount in most cases is between  1   ten thousand yuan and  6   ten thousand yuan. In extremely rare cases where the circumstances are particularly severe and the party at fault has a better economic condition, the compensation amount may be higher, but it will not generally reach astronomical figures. Many parties expect the  “several hundred thousand yuan in mental compensation”, which is relatively difficult to obtain in practice.

  It is necessary to clarify two points: first, compensation for damages and division of property are two independent claims. If infidelity constitutes a major fault, in addition to compensation for mental distress, the court will appropriately incline towards the innocent party in dividing the common property, and the two are not contradictory; second, if the innocent party discovers the other party's infidelity during marriage after the divorce agreement, as long as the claim for this right is not explicitly abandoned, the innocent party may still file a separate lawsuit to claim compensation for damages within three years from the date of knowing or should have known.

  Lawyers advise that after discovering the unfaithfulness of the other party, one should calmly collect evidence such as chat records, photos, videos, transfer receipts, and written materials admitted by the other party. Attention must be paid to the legality of the evidence collection method, as evidence obtained through illegal entry into someone's residence or through surreptitious filming and recording may be excluded. Marriage is built on loyalty, and those who cross the bottom line not only have to bear moral condemnation but will also inevitably pay the corresponding legal costs.