Responses
I mean, no
For example, a bisexual person that is NOT demisexual might have sex with someone they barely know, like for example a one night stand, or even the "3 month talking stage" does not fall into the demisexual umbrella, it's not just knowing the person and having sex with them
Literally anyone can be demisexual, could be lesbian and demi, gay and demi, straight and demi
Like I said before, demisexual people only feel attracted sexually to a person once they've had a bond or a deep emotional connection with the other party, so that bond or connection always depends on the person

i think it would make more sense for eunsan to be demisexual or something similar, because he's not really attracted to men besides ian. it's because they are already so close that i think something was able to grow between them