After seeing Will, holding him, he wanted more. Especially after seeing fucking Carlton. Why did Carlton get to have Will when he didn't even know him?
"Will-" Mike started.
"Don't let go," Will said, sniffling.
"Mike?" Will asked quietly.
"Yeah?" He answered.
"I love you."
________
Or Mike visits Will two years after graduating high school, and meets Carlton, Will's new boyfriend. Mike isn't a fan. He tries to let Will be happy; he wasn't here to ruin Will's relationship. He just missed Will.
Will is nervous about seeing Mike, and Carlton does not know everything about Mike. He doesn't know Will has loved him forever, or that they talk every week, or that Mike sends him all of his rough drafts for his books.
When they do see each other, their feelings become impossible to deny anymore.
Carlton is not happy.