Concubinage is an interpersonal and sexual relationship between a man and a woman in which the couple does not want, or cannot enter into a full marriage. Concubinage and marriage are often regarded as similar but mutually exclusive. In the Judeo-Christian world, the term concubine has almost exclusively been applied to women, although a cohabiting male may also be called a concubine. In the 21st century, concubinage is used in some Western countries as a gender neutral legal term to refer to cohabitation (including cohabitation between same-sex partners).