Non-monogamyNon-monogamy (or nonmonogamy) is an umbrella term for every practice or philosophy of non-dyadic intimate relationship that does not strictly hew to the standards of monogamy, particularly that of having only one person with whom to exchange sex, love, and/or affection. In that sense, "nonmonogamy" may be accurately applied to extramarital sex, group marriage, or polyamory.
MonogamyMonogamy (məˈnɒgəmi ) is a dyadic relationship in which two members of a group form an exclusive intimate partnership. Having only one partner at any one time, whether that be for life or whether that be serial monogamy, contrasts with various forms of non-monogamy (e.g., polygamy or polyamory). More generally, the term is used to describe the behavioral ecology and sexual selection of animal mating systems, referring to the state of having only one mate at any one given time.
InfidelityInfidelity (synonyms include cheating, straying, adultery, being unfaithful, two-timing, or having an affair) is a violation of a couple's emotional and/or sexual exclusivity that commonly results in feelings of anger, sexual jealousy, and rivalry. What constitutes infidelity depends on expectations within the relationship. In marital relationships, exclusivity is commonly assumed. Infidelity can cause psychological damage, including feelings of rage and betrayal, low sexual and personal confidence, and even post-traumatic stress disorder.
PolyamoryPolyamory () is the practice of, or desire for, romantic relationships with more than one partner at the same time, with the informed consent of all partners involved. People who identify as polyamorous may believe in open relationships with a conscious management of jealousy and reject the view that sexual and relational exclusivity (monogamy) are prerequisite for deep, committed, long-term, loving relationships. Others prefer to restrict their sexual activity to only members of the group, a closed polyamorous relationship that is usually referred to as polyfidelity.