Well, i didn't read the topic yet, but i'm gonna tell you what i know about it. When it comes about this things i would never take advice from anyone except from me; I do know what i'm talking about… let's say that
It's all about chemistry and Situations that can happen, there are an infinity of situations, interest can happen suddenly and no one can control your own libido.
Believe me, i've seen straight guys falling in love with EACH OTHER. it's all about proximity and situations that can take you somewhere.
Society only works this way because it was "built" this way, but believe me. all of this can change in one second.
THE ONLY THING i think you should first do is. IF YOU LIKE HIM, be close to him, or you will probably never get anything!
Maybe have some fun together? or maybe not? If he thinks you are a nice person, it maybe happen, it maybe do not. i've also seen the opposite, two dudes who thought they hated each other, ended you liking each other. MY POINT IS: there is NO RULE on this. just break the wall (the wall that actually does not exist) and maybe he will care about you!
BUT IF THIS DON'T HAPPEN, believe is, IT'S NOT because he is Straight. it is just because IT DIDN'T HAPPENED! no one can ever show you an example, because every situation is a different situation.
i'm not trying the prove anything to anyone here, but that's the truth! Some people are too "let's follow the world the way it is" they think there is something "concrete" about society, they just don't get it!