Infidelity is a violation of a couple's emotional and/or sexual exclusivity that commonly results in feelings of anger, sexual jealousy, and rivalry.

Adultery is extramarital sex that is considered objectionable on social, religious, moral, or legal grounds. Although the sexual activities that constitute adultery vary, as well as the social, religious, and legal consequences, the concept exists in many cultures and shares some similarities in Christianity, Judaism and Islam. Adultery is viewed by many jurisdictions as offensive to public morals, undermining the marriage relationship.