Non-monogamy is a type of interpersonal relationship in which sexual exclusivity is not held as the primary fundamental premise of the relationship. Individuals may form multiple and simultaneous sexual or romantic bonds. This can be contrasted with its opposite, monogamy, and yet may arise from the same psychology. The term has been criticized as it may imply that monogamy is the norm and that other ways of relating are deviations.
Many non-monogamous terms are flexible in definition, because they are based on criteria such as "relationship" or "love" that are themselves variably defined. In addition, usage creates distinctions beyond the raw definitions of the words. Thus, even though some relationships might technically be considered both polygamous and polyamorous, "polygamy" usually signifies a codified form of multiple marriage, based on established religious teachings, while "polyamory" is based on the preferences of the participants rather than social custom or established precedent.
Forms of non-monogamy include: