A marriage in which both spouses agree ahead of time to accept sexual relations by either partner with others is sometimes referred to as an open marriage or the swinging lifestyle. Polyamory, meaning the practice, desire, or acceptance of intimate relationships that are not exclusive with respect to other sexual or intimate relationships, with knowledge and consent of everyone involved, sometimes involves such marriages. Swinging and open marriages are both a form of non-monogamy, and the spouses would not view the sexual relations as objectionable. However, irrespective of the stated views of the partners, extra-marital relations could still be considered a crime in some legal jurisdictions which criminalize adultery.