Sort of an odd thing I noticed the other day- My daughter and I were out visiting a friend, and as we were conversing, the daughter-unit was feeling a bit shy, but wanted to have certain stories shared, so was requesting that I recount the stories to "them". There was just the three of us present, and she's pretty good with pronouns, but I just wrote it off as misspoken. This occurred several times during the conversation though, and it became apparent to me that she thinks of other poly folk in the multiple sense. Even if you're partners aren't present, or if you're poly-single, she seems to apply plural pronouns when speaking with poly types.
Hmmm... that was an interesting idea! "We"us", and "them" sort of come as part of the package for her when around others that are poly, and I realized that I often think of other poly folk in the plural as well. It's an expansion of the couple dynamic that often develops when there is a longer-term connection that is palpable to others, where you begin to think "maryandjohn" instead of Mary and John. Typically for me, it's more highly related to the information that I have about someones relationships sphere. Let's say J has three other partners that I have met, I often think about J within the context of their connections, and not only as an individual. For her, it's a community thing. If she knows that someone we are around also is poly, she thinks of that person as a portion of the community that is around her, and therefore likely plural in some fashion.
There isn't really a value judgment to attach to this habit, but I think that I will be more conscious of my verbiage regarding others for a while. Fuzzy words lead to fuzzy thought, so the saying goes, and clarity is a quality I value. At the same point, there is a sense of comfort with the idea of belonging to a community, a family, a pod, unit of socialization, part of something bigger than myself that is accepting of how I choose to express myself. We think that's worth a few plural thoughts every now and again. ;)