My sister doesn’t know that I can see her tumblr blog description that describes her as bisexual, agender, “them” pronouns. I want to refer to her as she wants but I also don’t want her to know I know since I don’t actually know who she’s told. How?
Rock on – you are a sensitive and supportive sibling and I truly appreciate your question; I’m sure your sibling would too, if they knew that you are being so careful and conscientious.
Your dilemma seems to be: how do I support my sibling without violating their boundaries? The bare fact fact that you want to act from an affirming place by using their pronouns is, to my mind, an excellent reason for sitting down with your sibling and just coming clean about what you found and how. The very best energy – i.e., how you approach the conversation, with kindness and openness – and best intentions – which you have – can work wonders.
It seems, though, like you’re worried about your sibling’s reaction to you knowing. Without more information about your situation, I can’t be sure why. One reason I can guess at is that your sibling might be an intensely private person who keeps their gender and sexual identities away from family. If this is true, then part of the conversation would hopefully involve you acknowledging that there are reasons why your sibling did not tell you and validating these reasons, or, “I totally get why you wouldn’t want to share this with me and that’s cool.” Make it really clear that you understand why this choice was made, and that you are only bringing it up because you want to make them as comfortable as possible around you. The conversation will also have to address how to behave around other family members, including whether or not you should use your sibling’s chosen pronoun with others.
Another reason for your worry could be the quality and the history of relationship you have together. In deciding how to move forward, your best guide will be this relationship. Do you generally support each other in other family issues? Do you ‘share the spotlight’ well in your family gatherings and conversations i.e., do you fight for control or attention of other family members? Do you have a history of trusting each other or breaking each other’s trust? Do you share friends or interests or other common ground? I ask these questions because gender stuff never happens outside of already-existing relationships. The reason why a sibling or a parent might refuse to use one’s pronouns, for example, can be about an old hurt or bad dynamic and not about pronouns at all, in my view (see this). Same thing: the reason why you might be worried or why your conversation might be challenging might be because of your history with your sibling that makes any big conversation challenging, and not because of its topic.
In either case / for either reason (apologies if I’m completely off-base and please feel free to write back), I think it might be helpful to plan the conversation in a way that makes it very different from how you usually interact and spend time with your sibling in order to make it clear that this is different and important. OR, take advance of a fun and familiar ritual that you do together or place you go. These are different tacks, but they both send the message that you are being intentional, thoughtful and caring (more tips here).
Good luck, and take courage from knowing that you are already being a really lovely ally in seeking out resources and asking questions.
Hope that helps,