Adultery is generally defined as extramarital sex that is or was considered objectionable on social, religious and moral grounds, and which often resulted in legal consequences. Although the sexual activities that can be described as adultery vary, as well as their consequences, the concept is found in many cultures and shares similarities in Judaism, Christianity and Islam. Adultery was and continues to be viewed by many societies as offensive to public morals, and as undermining the "marital" relationship.
Historically, many cultures considered adultery a sin and a very serious crime, sometimes subject to severe penalties, usually for the woman and sometimes for the man, with penalties including capital punishment, mutilation, or torture. In most Western countries during the 19th century, most direct criminal penalties have fallen into disfavor. Since the 20th century, criminal laws against adultery have become controversial, with most Western countries repealing adultery laws. In countries where adultery is still a criminal offense, punishments range from a fine to caning and even capital punishment.