There is currently an interesting post about bisexuality on the Mary Sue dissecting an interview Robert Karjel had with the Guardian.
It’s incredibly sad reading both the interview and the discussion on the Mary Sue comments that many people out there are scared or get annoyed when a character (specifically male characters) is revealed to be Bisexual.
I would also like to add that it isn’t just straight bigots who contribute to this sort of mentality. As many Bisexuals can attests to, parts of the LGBTQ+ can be just as biphobic, ignoring their blights, considering them as “really just Gay” and treat them with distrust.
I think Red Ultron says it best:
The part you always hear is that bit about “hidden agendas”. I mean all the time. But someone’s sexuality isn’t an agenda. It is a characteristic.
This is no different than someone saying they should have been warned because the protagonist was Latino or female or bald.