I like the idea of Anna and Kristoff getting engaged in kind of the same way their first kiss happened. I mean, Kristoff doesn’t propose, the subject just comes up by accident, because Kristoff gets too excited.
For example. They’re just talking about whatever, Kristoff saying something like “You know, once we get married–I mean, if we get married… Wait, what.“ And Anna’s just smirking, because yes, she knows what you mean, Kristoff. Maybe teasing him a little with “So, you want to marry me, huh?“
This would probably happen a few years into their relationship. I just don’t think they’re the kind of couple who would propose, but instead talk about it before coming to a mutual agreement to get engaged.
I’m sorry if nothing of that made sense, I just had to write my thoughts down..