I recently came out to a friend, and I thought that it went well. She was open to new ideas, and willing to discuss them, though she disagreed with it overall. However, she is very motherly and protective toward animals. As it turns out my admission bothered her more than I thought: she said she started having nightmares since the first time I told her about (I described my first experiences, though I was intentionally vague to avoid offense). According to her, she thought she could handle it by reading more about it (from sources I recommended, though I don't know what else she looked up).
She has since insisted I stop talking to her about it, and I will certainly do that out of respect to her. She is kind enough, and knows me well enough, that she won't tell anyone else, nor does she appear to think that I would actually hurt an animal. I don't think there's much risk of her damaging me in general, out of mutual respect and friendship. But now I feel terrible for having told her about it at all, for her hurt feelings (regardless of whether they're justified or not). I told her nothing explicit: just first experiences (which are all kisses and hugs), and a couple polite and calm arguments about animal consent and possible harm, etc.
My questions are, what did I do wrong, if anything? I know that she wasn't the best choice to come out to (I had to do it to refine my position, since I knew she would disagree and also be calm enough to discuss it in the moment). Is there anything I can do to relieve her anguish? Or is leaving it alone my best option? I feel, for the first time, like telling someone has done them harm, and want to avoid doing that in the future.
I don't think you did anything wrong beyond misjudge her reaction. Imo what you're already doing by not talking about it anymore is all you can do at the moment. Maybe I'm a bit biased from my own problems, but sometimes it can be difficult to tell if bringing up an issue will make it better or worse, so leaving it alone until an opening is more clear is probably best.
I wouldn't bring up the conversation for a few days. I would wait for her to bring it up again.
Don't beat yourself up over it. You have no obligation to feel guilty that your sexuality upsets someone. I would be careful about coming out as zoo to anyone, though.
Her reaction sounds more like something problematic from her past than anything else. Nightmares seems an extreme reaction to gentle talk about sex. Unfortunately, she has closed off your ability to help until she decides to talk to you about it.
Also, when you tell someone you actually make them an accessory so they might have a legal requirement to tell on you or face charges themselves. So be careful what you open up about.
There's nothing legally difficult about what I said. Even if I had gone into full details, no charges could be filed now, and most of it was completely legal.
Not saying there was specifically in your case but some folks aren't from zoo safe states etc.
It's easy to forget after talking to this kind of community that to most people, zoophilia is really, really weird at best, and aborhent and vile to most people, for the reason you mention, which is people feel like parents to children in regards to their pets.
When you come out to anyone, this is the risk you face and there might not be anything you can do about it.
She said not to talk about it, so I would leave it be unless she wants to bring it up herself.
Not to state the obvious, but people don't have a good outlook on anything zoo. I can't imagine what you expected or what you were thinking or how you imagined a good outcome instead of a disaster.
I wouldn't worry about refining arguments for a position in support of something that 99% of everybody doesn't support and can't talk about without having a lot of negative personal judgments against you that will compromise loving relationships.
You may have just lost a friend. If you want to know what your mistake is, it is a lack of being careful.
Next time, bring it up without admitting anything. Just talk about the acts of other people like it's something you saw in the news and get a little idea of how someone else thinks and feels about this. If they're violently against it, and scared stiff, then you know that's something you don't talk about.