Interesting. I've never thought of the bisexual thing in those terms, but you are of course right, that interpretation could be a danger. I know I have always found fics that make the blunt statement 'all vamps are bisexual' to be tiresome but that is mainly because I dislike the simplification and imperative implied.
The only way round it I can see is to simply declare that evil moral deviation does involve throwing away the bathwater (pointless cultural taboos) as well as the baby of morality. I think it is impossible to write the vamps and suggest that every single thing they do is evil, so one has to have a more fluid approach to morality and the meaning of their actions. Most fic does this without thinking about it by simply representing them in entirely human terms. It is very rare to read fic that deals with the vampires behaving towards outsiders in a vampiric fashion, all unpleasantness (and pleasantness) being entirely within-family. But then most historical fic doesn't try to achieve period morals either so the original dilemma I mentioned is rare.
But when it comes to the bisexual thing that is a concept found in modern fic that the vamps can reasonably be expected to have and that is also part of modern morality so it isn't being presented as a deviation in that sense but just something the vamps may have absorbed from the culture around them. just as female emancipation in modern vamps won't come across as deviant.
So you only get the bisexual thing being a moral problem in a historical fic that aims for period morals and also states bisexuality is a vampiric thing. Offhand I can only think of one writer who has done that and she did it in separate stories and is a good enough writer for it not to have bothered me anyway.
For my own writing I don't think it's a problem because I have never seen vampire sexuality as equivalent to human bisexuality. For me vampire sexuality is something very different, rather animalistic. Based more on power dynamics than attraction or sexual requirements. This just happens to be the way I write it but it does coincidentally remove the moral dilemma.
no subject
I think it is impossible to write the vamps and suggest that every single thing they do is evil, so one has to have a more fluid approach to morality and the meaning of their actions. Most fic does this without thinking about it by simply representing them in entirely human terms. It is very rare to read fic that deals with the vampires behaving towards outsiders in a vampiric fashion, all unpleasantness (and pleasantness) being entirely within-family. But then most historical fic doesn't try to achieve period morals either so the original dilemma I mentioned is rare.
But when it comes to the bisexual thing that is a concept found in modern fic that the vamps can reasonably be expected to have and that is also part of modern morality so it isn't being presented as a deviation in that sense but just something the vamps may have absorbed from the culture around them. just as female emancipation in modern vamps won't come across as deviant.
So you only get the bisexual thing being a moral problem in a historical fic that aims for period morals and also states bisexuality is a vampiric thing. Offhand I can only think of one writer who has done that and she did it in separate stories and is a good enough writer for it not to have bothered me anyway.
For my own writing I don't think it's a problem because I have never seen vampire sexuality as equivalent to human bisexuality. For me vampire sexuality is something very different, rather animalistic. Based more on power dynamics than attraction or sexual requirements. This just happens to be the way I write it but it does coincidentally remove the moral dilemma.