I personally identify as polyamorous, but I have a lot of worry over whether other polyam people would accept that label for me because I don't want to be in another relationship besides my primary one. I do want to pursue romantic feelings and have done in the past, and recently I've been thinking about the possibility of dating other people casually besides my boyfriend, but is it okay to identify as polyamorous if you don't desire more than one relationship?
You can identify however you want, and other people don’t really need to be okay with it. It is totally okay to only want one “relationship” but be open to “casually date” other people. If that is polyamory to you, that’s fine! You could also identify as monogamish, polyflexible, or “in an open relationship.”
However, some polyamorous people are not super into the idea of dating someone who already has a primary relationship and doesn’t want another relationship, but only wants a fling or something casual. Other people are okay having a low-stakes, casual fling - but then if one person or both people develop stronger feelings, it can get complicated. It’s important that you are really up front with everyone about the primacy of your current relationship and what you can and can’t offer to potential dates.
If you’re not out there in the polyamorous community or dating world, not seeking casual flings, not trying to date anyone - then it really doesn’t matter what you call yourself. You can privately identify as polyamorous to recognize the fact that you could, someday, maybe see yourself casually getting with another person. But the point of language is to help us be clear and honest with each other as well as ourselves, so just identifying as “polyamorous” without qualifiers or caveats could cause some pain, since it usually implies a willingness to pursue other relationships - something you don’t include in your personal polyamorous relationship.
It’s not about whether other people agree that you’re allowed to use a term - it’s about whether your use of that term is helpful, accurate, and healthy for everyone involved. If you use the identifier “polyamorous” alongside clear and honest delineation of your boundaries and limits, that’s one thing. Some people might hear your limits and qualifiers and say “that’s not really polyamory,” and they’re entitled to their opinion, but they can’t take the word away from you. Make sure that you really know why you want to use that term, what it means to you, and do your best to listen openly if other people try to explain that something you’re doing is causing problems for them or their community.