Polyamory is the ability to love, build relationships not with one person, but with several, with the approval of all participants. Here are a few quotes from Wikipedia
Polyamory (anc.-greek. πολύς — “many, several” Latin. amor — love) — a system of ethical views of love that allows the possibility of multiple love relationships between one person and several people (and also between several people) simultaneously, with the consent and approval of all participants in this relationship..
Adherents of polyamory attach great importance to ethical crimes of poly-familial relations and ideally seek to build their relationships on the basis of love, respect, trust and loyalty. The key to building and maintaining functional poly-familial relations, they consider accessible, honest and complete discussion of all participants in the relationship of all issues of interest to them. Such discussions are an integral and essential part of the polyamorous lifestyle. They enable all participants to exchange information, and jointly seek solutions that take into account the interests and needs of everyone. Polyamory, as a system of views based on the belief that such destructive and restrictive emotions as jealousy and possessiveness should not define human relations and manage them. Recognizing the existence of these emotions, which are naturally inherent in many people, supporters of polyamory believe that these emotions can be learned to own, thereby getting rid of their power over themselves.
Sex is not always the main determining factor in polyamorous relationships. Such relationships often unite three or more participants, tend to have a long-term relationship in which sex can be one of the defining parties, but not necessarily their basis.
One should not think that polyamory is only when 3 or 4 people live under the same roof as one family. In our reality, this is not always possible. But to be friends with families, be close at the same time both spiritually and sexually – very real. Moreover, the joy of such communication is more than just from sexual intimacy, because we enjoy both bodies and souls of each other. It is not entirely clear to us why society imposed on people – friendship and sexual attraction – are incompatible. Very compatible! But, true, this requires a great deal of mutual trust in the family.
To get acquainted with the ideas of polyamory, we recommend the site
Very good article on the theme of polyamory
About children in poly-families