I'm kind of new to OFMD fandom and I've been hearing some confusing stuff about how there's a lot of hostility to people headcanoning Ed as gay instead of bisexual, but I can't tell if it's just a fandom slapfight or if there's a real harassment problem going on or what. I know you've talked about Ed identifying as gay not bi, have people said anything to you about it?
no, since 2022 people have been headcanoning ed teach as gay, bisexual, mostly-gay-but-he-does-make-exceptions (that one's my take but i've never been alone in it), ace, demi, pan, and pretty much any other variation you can imagine except heterosexual, and although all of them are debated and "gay" and "bi" are the clear frontrunners, they're all pretty widely accepted. the bisexual ed guys celebrated after david jenkins said he's a disastercule believer, as is their right, but generally people understand that "are extracanonical statements by the showrunner about his own headcanons part of canon?" is a question where both answers are perfectly valid and it's just down to personal preference.
it's only an issue if you're an asshole about other interpretations. there are some people (and i do mean multiple people; there's one in particular who tends to be loudest about it so i want to be clear that they are not the only one) who do have a history of being an asshole about other interpretations (and usually this isn't the only topic they're like that about!), and then when people finally start pushing back on that, they'll describe this pushback as "people harassed me for my headcanon" when it's actually "people got mad at me because i spent months loudly insisting that every other interpretation besides my own headcanon was stupid and problematic" and/or "people got mad at me because a specific argument i used to support my headcanon was offensive."
in the case of people who object to bisexual ed headcanons some issues have been:
repeatedly insisting that people who interpret ed as bisexual are obliged to provide you with justification in the form of meta on the topic (NB: meta on the topic already exists and has since 2022), and if they don't, it proves they're just fetishizing bisexuality. (note that this is just a dressed-up version of the classic redditor "it's not that i object to queer characters, it just needs to be relevant to the plot or else it's unnecessary forced diversity")
repeatedly insisting not only that you don't personally consider david jenkins' extracanonical statements about the disastercule stuff to be canon, or even just that you personally find it kind of annoying that so many other people do, but that anyone who does incorporate them into their view of canon is objectively wrong and stupid
insisting that the only reason anyone would interpret ed as bisexual is because they are sexually attracted to him and are objectifying him (and, moreover, that there's something inherently wrong with letting what you find hot influence how you interpret a work of fiction)
doing callouts for fic where ed is depicted having sex with a woman on grounds that this not just a characterization you don't personally agree with, but an erasure of his canonical monosexual orientation
becoming suddenly hostile to female characters in the show when you find out people who think of ed as bisexual are headcanoning them as ed's past lovers (i'm thinking of some people who had pretty positive - i actually thought somewhat overly positive - takes on anne & mary until the disastercule stuff took off, at which point they suddenly switched to describing them as hatefully abusive)
describing any sort of fic or other content where ed is depicted as having had sexual relationships with both men and women, regardless of context, as making him a "slut" and therefore being a problematic depiction of bisexuality
generally reacting with extreme hostility to the existence of such content, for instance describing the existence of a disastercule fic event as "a weekend dedicated to being assholes" and repeatedly angrily demanding tags for an event that already had established tags, which no one had ever suggested they would not use
...and honestly even if you did say something in one of these bullet points you'd probably be fine if it were a one-off. it's only if you have a very well established long-term pattern of repeatedly and belligerently doing multiple things on this list that people are going to think you are just being biphobic about this. and if that happens, it is disingenuous to describe this to others as "people got mad at me for saying i don't think ed's bisexual." that's not what happened.
(and none of this is really specific to the bisexual ed stuff! various people have acted like this about lots of other issues in this and every other fandom.)
"i interpret ed as gay not bi because i don't consider david jenkins's statements outside canon to affect my interpretation" and "i interpret ed as gay not bi because i just don't think his interactions with anne and mary express the kind of raw sexual chemistry he exudes around jack" and "i interpret ed as gay not bi because i think it's hotter that way" and "i interpret ed as gay not bi because i'm gay and it makes me happier to think my favorite character has this in common with me" and "i interpret ed as gay not bi because idk that's just kind of the vibe i get from him" and "i interpret ed as gay not bi because i carefully considered the fullness of the canonical evidence and i truly believe that's the best supported take" are all absolutely valid reads and you can say them around here without anyone getting mad at you, as long as you're not an asshole about it. i know that because people including me have been doing that since 2022.