Note 12 at 1 Cor. 6:16: This is an amazing statement that very few people have thought through. An individual doesn't have to enter into a legal marriage with another person to become one flesh with them. Any adulterous relationship produces this one flesh union (see note 4 at Mt. 19:5, p. 381). An ignorance of this has led many people into illicit sex thinking that when it's over, it's over. Such is not the case.