how to make someone asexual/demisexual like you?

I don't know if I'm a bit late to the party but I just wanna put my two-cents in. I'm dating an asexual (I would consider him demisexual, to be honest) man. What attracted him to me the most was that I was a very good friend. Unfortunately, he has had a lot of female friends develop crushes on him, force their feelings on them, or confess their love even when he was in a relationship. Because of this, he has lost contact or has become very distant to a lot of people who could've been close friends. I, however, made sure not to develop those feelings for him. I had a small crush on him at one point but it wasn't a big deal to me. I was able to treat him like a friend and he did not have to worry about me developing feelings for him that he could not return (he was dating someone at the time). He felt he could rely on me and was able to express and open himself up to me, thus letting our friendship grow...and our friendship continued to grow to the point where we decided we wanted to be committed to each other. I don't know if it is with him specifically or most asexuals and demisexuals out there, but I think not pressuring them and trying to change them to fit your romantic/sexual desires is a big plus in regards to having one develop feelings for you.