The practice of being in multiple committed romantic relationships.
Well, allegedly. Mostly an excuse for sleeping around, as far as I (ChiarkPerson) have seen.
That too, to be honest. I've seen it used for both. I've USED it for both. -ElliottBelser, not that he thinks sleeping around is a bad thing, assuming everyone involved is happy about it
Can be distinguished from the practice of being a total and horrendous two-timing cad with the following differences:
Firstly, all partners in a polyamorous relationship know of each other's existence, at least.
Secondly, what constitutes "cheating" is discussed by all the involved parties at length - a delicate process involving a lot of negotiation. (Is it cheating if your primary partner isn't in the room? And so forth.)
Naturally controversial, as MonoAmory? and MonoGamy? are considered the norm in western culture. ElliottBelser adds an emphasis on "considered" because, in his opinion, even the most devoted monoamorous couple has to set down ground rules about "You can look but you cannot touch other people" and this, that and the other.
BiSexuality helps but isn't strictly needed to make this work. Far more neccessary is a fair bit of willingness to discuss painful emotions, as Jealousyjust happens in these kind of relationships. (Or any kind, really).
For further reading on the subject, ElliottBelser and pretty much his entire circle of friends who are "poly" highly recommend /TheEthicalSlut?.