When you have a falling out in a romantic relationship, you generally know where to go from there — usually, you either work through it and stay together, or you accept your differences and go your separate ways. But in a friendship, where there's less of an agreement (for lack of a better term) that you're going to stay together, it's not as clear-cut whether you'll make up or split up.
Then, before you know it, weeks go by, and you're both in completely different places in terms of your friendship.
"Part of that comes from the fact that with friendships, there’s not the expectation for monogamy," Dr. Bonior says. "You’re not expected to have only one friend, so it’s harder to tell [where to go from there]."