Disclaimer: I am not at all a part of the polyamory scene, I just enjoy playing with words and this came up on my doomscroll.
Obviously you can call them whatever you want, whether that's "Twigs" or "Divinities", no one has a right to tell you what words you may and may not use.
But that's obvious. The question you asked is what options are there, and that's a funner question.
Thinking only a few moments I like "Connections" but expect anyone other than me would interpret that with a degree of sterility.
There's "Friends with Benefits" or just "Hookups" but given the context, I think the word you're looking for must be one that implies more intimacy and meaning.
"Companions" just sounds like a Firefly reference but maybe it could work for others who don't make that association.
Fuck, I kind of like "Allies" but people will probably think you're talking about a role playing game.
Hmmm if you expand it to two words you open options like "Heart Friends" or "Deep Friends" or "Full Friends", I think that might strike people as really childishly poetic though.
A euphemistic and tongue-in-cheek name could be "Bed Friends", that probably still carries the casual tone of "Fuck Buddy" though.
Something less explicit but perhaps with too much unintended meaning would be "Supports". (Similar, "Pillars")
Oooh ooh I like this one, "Muse" carries a pretty intimate tone, though "Muses" maybe carries a tone of superiority... hmm
The rabbit hole my thoughts have gone down now is suggesting a single word for the category of people-you-sleep-with-and-also-have-relationships-with may be the problem. If instead you determine a word for each of these people describing what you love/like them for / value them specially for. This is the edge of my understanding of the polyamorous experience though, I'm not sure if the experience is so defined as to be described as a love this person because they are such an Imp of a person but you love this person because they feel like a God/Goddess and this other person is better described as a Rascal. Hmmm I don't like this avenue, this is basically the partners pet name but suggesting you use that word to describe your relationship to others in public is probably rarely appropriate.
My grandparents once asked me if I had any new "Squeezes", I think that carries a sufficiently intimate tone?
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