Demisexual character?

I was discussing my fantasy story and some of the main characters to a friend. I never really pinned down a firm sexuality on most of the characters. I know that sounds odd, but for a specific group of people in the story, they are just "sexual." They have heterosexual arranged marriages, but as to who they are romantic with, it's just about anyone. Extramarital relations are condoned and almost expected. It's not unusual for a happily married man or woman to have a same sex partner who also lives in the house.

Anyway, one of my characters is unusual because he has just about zero interest in sex. He has a completely unrequited crush on a married woman, but he doesn't think of her sexually. He attempts to start a physical relationship with her husband simply so he can be with her and possibly live with her as her husband's companion. It doesn't work out because he can't force himself to get interested. It's not because he's straight. It's just that he never really trusts the husband for various reasons related to the plot.

Anyway, several years later he gets romantic feelings for someone and they have a ... I don't know.. A non-sexual romance. This goes on for a few years until the woman says she wants to leave him because he has no sexual feelings. They split up, but get back together a few months later, because he's suddenly sexually attracted to her. Once he is with her, he's extremely passionate. He's in his mid 20s and basically he's only had one person he's ever wanted sex with and three people he's ever had romantic feelings for. ( husband, wife and girlfriend)

Anyway, I was concerned that perhaps this character had an unrealistic sexual identity. So I was talking about it to my friend. She said that quite the contrary. He sounded demisexual. I'd never even heard of this orientation. I've read up on it, but mostly just a list of facts that are a bit dry.I've never read any fiction with demisexual characters. I've never read any narratives that were written by demisexual about their experiences with love.

I'd like to make sure that I have an honest voice with this character. I don't want him to appear phony. Are there any resources out there where demisexual said talk about their experiences, rather than just listing characteristics of demisexual so. I want to make sure his feelings are genuine, if that makes any sense.

Oh there's a reason things change. It's plot related, so I didn't want to get into it. But basically he gradually does change his feelings, but he is wary of her because she shows signs that she doesn't trust him on some level. She keeps too many secrets. He only goes back to her when she finally works on being able to trust anyone at all.

Yeah,I don't know why I care about this character's sexuality so much. It's probably that I never heard of it before when someone mentioned it to me. I've got a married guy who loves his wife, but he has many boyfriends he rotates through. I don't really think of him as bisexual for some reason. I think if you were to ask him, he'd shrug and say, "I guess. Who isn't?" (Not everyone is. He's just that kind of guy.) As I mentioned in the original post, most of my characters are just "sexual." They aren't wild hot dogs, but they just see it more as something fun you can do with very good friends.

That may be another reason I think about him. He's sort of an anomaly in the story. I didn't originally write him to be that way, he just ended up that way. At first I just made him inhibited and prudish. But that made no sense, considering his background. And after a while writing his scenes, I realized that he really just had no interest. The only thing that bothers him about it is that if people find out, they don't see it's inappropriate to keep asking him, why? What happened to you? What's wrong with you. But he just finds it annoying and hurtful. He never feels shame about it.

And for some reason, I find that interesting about him. I know he's my character and I made him. But he seems to have very strong opinions and he was a minor character that just kept stealing the spotlight and getting more ingesting to me. He was a weak wooden prop that was barely a placeholder a few months ago.

I hope it's not over sharing, but in my research, I found this article. After reading it, I strongly suspect that I'm asexual, but very highly romantic. I thought since there were no psychological issues and I didn't actually get repulsed by sex, that I was just someone who didn't have much if any need for it. And what's creepy is that some of my "proof" that I wasn't asexual are specifically mentioned as very common issues asexual people face. So I'm a little bit... something about this.

So maybe this character fascinates me for reasons other than his complex psyche.

http://www.huffingtonpost.com/2013/06/17/asexuality-the-x-in-a-sexual-world_n_3444417.html