Dustin never had trouble looking at El. He loved to watch her use her powers, he loved to witness how badass she could be, he was always happy to see her, and even when she was in pain, he held her hand and kept looking at her, trying to find some way to help.
And when she looked back at him, he always smiled. He was always happy to see her, no matter the circumstances.
However... Something shifted in the past few days. Whenever he looked at El, she was already looking at him. Is it possible that her stare got more intense as they grew up? No, that's not right—she's not staring the way she used to, like a kid that has never been told it's rude to stare. Her eyes are softer now; sadder, maybe. If Dustin didn't know better, he'd say she's... Wistful. But he couldn't tell why she'd look at him like that.
It was puzzling, for sure. And now Dustin didn't know what to do. If he smiled at her when their eyes met, she would look away. Sometimes he'd catch her staring and wave at her, and she would just leave and go do something else. Should he just stop looking?
But Dustin looking at El wasn't the problem, was it? She'd get like that when they talked, too. Sometimes they would be chatting, and she would ask him something, he would answer it and then she'd stare at him in that way again. And when they were together like that, the weight of it would hit that much harder. Specially because El is too honest, at times, so she'd say something... Nice, about Dustin. Really nice. To the point where he'd feel his breath catch, or his face warm up, or his stomach swoop. And then Dustin would be the one to look away, because what the hell is he supposed to do with that? Those feelings are definitely dangerous. And, and, unrequited. El probably doesn't even mean anything by it! She's probably thinking about something else and her eyes just happen to land on Dustin every time. She's probably asking him questions about himself to contrast them to something (someone) else! She can be nice about him, she's probably nice about all her friends!
Dustin is not special. This isn't about him.