If i may, i'm afraid this issue is outside of the narrative. There are a lot of self insert MCs in this medium, and pickier readers may expect to have their preferences represented. I find this saturation has become detrimental, since most protagonists end up having a mute personality, and there's a lack of incentive for people to experience stories from "not their own perspective".
On the matter of Asterion's preferences, i fully support wathever you decide to do with it, and would ask that readers respect his sexuality much like they would a real person. Because, i believe, your story is bringing actual characters to life, as opposed to some form of virtual-adult-toy.