Ugh I'm in a somewhat similar boat also with a straight guy

Like I'll admire all these little things about him like the way he looks while paying attention in class. It sucks so bad because in the moment I interpret every interaction we have as something more than platonic when, objectively, I know he just thinks of me as someone he's friends with. In your case since you seem really close with him, I'd just keep the friendship intact unless he initiates anything. I hope it helps knowing you're not alone dealing with this.