Adultery is a word used in religious texts like Exodus 20:14. It applies to a married person sleeping with someone other than the person who they are married to. Adultery usually comes with a heavy punishment for example, death by stoning in some Muslim countries. In most countries adultery is no longer a crime, but most people still see it as a bad thing.(see Gospel of John 8) If a person who is married takes part in adultery, that person's husband or wife would usually have the right to be able to go to court to divorce them.