You know what I think?
I think Derek actually is the one who had Stiles questioning if he only liked girls.
I feel like at first he just realized “huh, he’s so goodlooking wow.” Then that morphed into like a sexual thing. Like he only really saw Derek’s good looks and the whole cool werewolf thing as his only good qualities at first because ya know, they used to hate each other.
So it made Stiles question but he could easily brush it off at first because he’s still a teenager and he doesn’t have it all figured out yet, the whole “this is just a phase” thing.
But then he actually starts liking Derek, in a “we’re sort of an odd duo, but we do make a pretty good pair” (of friends!!!!). Like they actually got passed the “you need me to survive that’s why you’re helping” stage. He really just genuinely started liking Derek, just calm friendly like at first, but that like into more of a crush like than a friend like without him even noticing.
And he feels it there but he just avoids it but then that night at the glow in the dark party? Kaitlyn asks the golden question, “do you?”
And he just sits there for a while. His mind immediately flashes to Derek and he thinks like “wait a minute, I actually fucking might,” like guys, that is.
Stiles sort of realizes it’s become more than “you’re hot and I wanna experiment,” and more than, “I actually don’t mind hanging out with you anymore, it’s kind of cool because you’re not as much of a shitty person as I thought you were.” It’s more of a “I really think I’m falling for you but I’ve liked girls my whole life and we used to hate each other. What’s going on?”
So he doesn’t get the chance to ever answer because he really isn’t sure at first. But the thoughts after that question are stuck with him. And overtime, he starts noticing little things about Derek, like really taking note. Like Derek’s actually smart and actually selfless and his bunny teeth and how he’s actually funny when he tries (it’s a bland and dry humor, snarky remarks when they bicker and Stiles gets sarcastic but Stiles appreciates and enjoys it regardless). Stiles starts realizing all these things that could factor into why he might actually like Derek (if he does because he isn’t 100% on that yet).
He starts realizing that Derek really isn’t the guy he met back in the woods, that Derek is more, that Derek is actually a great person under that hard exterior. He starts realizing how he used to get and still gets whenever something goes wrong with Derek, how he starts worrying and all. He starts looking at Derek in a new way, looks when Derek is oblivious, sort of the whole “admire from afar” thing, and can hardly help it, can hardly deny that he starts getting a little happier whenever Derek comes around, but he’s still, in a way, denial.
The night Derek almost dies changed that because for a brief moment he felt like he stopped breathing as he watched Derek bleed out on the ground.
He felt numb and he wanted to stay but knew he couldn’t. All he could do was hope that Derek would still be well and alive in the morning, that they would all be, and then he’d be able to tell Derek because he knew completely. Knew what it felt like to almost lose someone you care about so much.
Stiles wasn’t sure what he was going to say, how Derek would take it or how it would effect them, but it didn’t really matter in the end because he never got to say it.
Derek left and Stiles couldn’t even be mad because he knew Derek needed it, deserved it.
So, life went on and he tried to shove his feelings aside because it didn’t really matter anymore.
Except it did, which he realizes on the night at the school, seeing Derek’s initials.
I’d like to think that the reason for Stiles’ smile was because he had fully come to term with the fact that he did indeed have feelings for Derek. He wasn’t able to tell Derek, but he could finally admit it to himself.
No more questioning, no more “this is just a phase.” None of that.
Stiles just accepted it, and he was okay with it.