When you date someone, you have the markers along the way, right: you kiss, you have the talk, you say the three little words, you sit on a swing set and break up. You can plot the points on a graph. And you check up with each other along the way: Can I do this? If I say this, will you say it back?
But with friendship, there’s nothing like that. Being in a relationship, that’s something you choose. Being friends, that’s just something you are.