The last time that Bonnibel kissed Finn before the finale was all the way back in season 3, in “Wizard Battle.” It was one of their two overtly romantic kisses in the series, and the only one where she was at her normal age, but it was also lacking in emotion on her side, and she even followed it by slapping him. Even though she didn’t really have to do it, because he cheated, she was still treating that kiss as a “prize.” She was going along with the regressive ideology that because Finn had protected her, she had to repay him somehow using her body. This is a trope that we see all the time in television, but it wasn’t what Finn wanted; he wanted Bonnibel to actually like him, and her casually flirtatious behavior wasn’t a sign that she cared about him, it was actually the opposite.
When Finn gets over his crush on Bonnibel, he realizes that they don’t have nearly as strong a relationship as he once thought. Simply put, they don’t trust each other. See the events of “Burning Low,” “The Lich,” and “Too Young.” Since their relationship has always been founded on this sense of infatuation and hollow flirtation, they never learned how to be normal friends. It’s only after Finn starts seeing Bonnibel as a complex person rather than simply a potential romantic partner, that they realize how much they care about each other and enjoy spending time together. This is such an important moment for Finn; when he realizes that he feels happier being Bonnie’s friend, and that he doesn’t need a romantic relationship with her to value what they have.
And so, we come back to their last kiss. Unlike the kiss in Wizard Battle, it’s not a romantic kiss, it’s a simple kiss on the cheek, an expression of platonic affection. It’s not something she does to reward him, or manipulate him, or elicit a reaction out of him. It’s just her way of saying that she loves him. And he doesn’t look surprised or flustered like he did every other time she’d kissed him before, because he finally knows what their relationship is, and how much the two of them really care about each other. They’ve both grown so much.







