Anhkah Beloved Consort of Angels's blog: "Polyamory"

Polyamory (from poly=multiple + amor=love) is the desire, practice, or acceptance of having more than one loving, intimate relationship at a time with the full knowledge and consent of everyone involved. Polyamorous perspectives differ from monogamous perspectives, in that they respect a partner's wish to have second or further meaningful relationships and to accommodate these alongside their existing relationships.

The term polyamory is sometimes abbreviated to poly, especially as a form of self-description, and is sometimes described as consensual and/or responsible non-monogamy. Polyamory is usually taken as a description of a lifestyle or relational choice and philosophy, rather than of individuals' actual relationship status at a given moment. There is a certain fluidity in its definition, to accommodate the different shades of meaning which might be covered. Polyamorous relationships are themselves varied, reflecting the choices and philosophies of the individuals concerned.

Polyamory is distinct from polygamy, being closer to a personal outlook than a predefined bonding system. It is grounded in such concepts as choice, trust, equality of freewill, and the more novel idea of compersion, rather than in cultural or religious tradition.

Because of its fluid nature, polyamory is not clearly defined. Though there is no general agreement on its exact boundaries, people who identify as polyamorous typically reject the view that sexual and relational exclusivity are always necessary for long-term loving relationships. Those who are open to or emotionally suited for a polyamorous lifestyle may at times be single, or in monogamous relationships, but are more typically involved in multiple long term relationships.

Sex is not necessarily a primary focus in polyamorous relationships. It is common to find groups of more than two people who are living together, and seeking to build a long-term future together, with sex as only one aspect of their relationship.[citation needed]

Polyamorous relationships, in practice, are highly varied and individualized. Ideally they are built upon values of trust, loyalty, negotiation, and compersion, as well as rejection of jealousy, possessiveness, and restrictive cultural standards.[1] Such relationships are often expected to be more fluid and changeable than the traditional "dating and marriage" model of long-term relationships, and the participants in a polyamorous relationship may not have preconceptions as to duration.

More at http://en.wikipedia.org/wiki/Polyamory