I so really love the headcanon of Mike not confessing his feelings to Will until they’re adults. Like mid twenties, out of college, and home figuring out life’s next steps.
I just think they’re both too lost by the end of the show to somehow figure out they could be together. I love the idea of Mike being able to find himself in college, time to mourn El, space to see what their relationship really was like with adult eyes. New people to love and experiment with and just learning what the difference is like when you get to kiss someone you’re actually attracted to. To experience people outside of Hawkins and to give himself time to begin to heal from all the mistakes he made as a kid, to understand he was just a kid and he did the best he could. To understand how the default straightness he was put in isn’t the only way to be.
Space for Will to see how other people can perceive him, and know him, and love him more for it. Making friends, experiencing the queer scene in NYC art school. For him to learn to love himself and gain more self confidence and accept that, while Mike was his first love, it’s far from his last. For him to get to feel as normal as he can for once in his life.
I love the idea of every break, when they see each other there’s something there, that’s not addressed because how do you bring it up? When the relationship they’ve had so far is built on doubt? When you only have a few weeks or months together before it’s back to weekly phone calls?
Mike starts to see that it’s more than just how deeply he loves his best friend as he experiences new romance and new friends over the years. He sees the part of himself that romantically longs for Will.
Will feels that spark of first love every break, but it goes from being a weight he doesn’t know how to carry, to being bittersweet. Something he knows will never fully go away but something he can live with because he knows there so much love in the world for him.
And when they graduate and come home and talk about the future, where to move and who they want to be, they realize they can’t be anything without each other. And when Mike starts showing real interest Will can allow himself to have real hope again.
The snowball can finally become an avalanche.