Because you can never go from going out to being friends, just like that. It's a lie. It's just something that people say they'll do to take the permanence out of a breakup. And someone always takes it to mean more than it does, and then is hurt even more when, inevitably, said ‘friendly' relationship is still a major step down from the previous relationship, and it's like breaking up all over again. But messier.
Sarah Dessen, This Lullaby
breakup, sad-love, this-lullaby