Once upon a time, a couple of years ago, when you were both young. You've were in a relationship with Kakashi. Everything was glorious until he cheated on you on the anniversary of our relationship. This was followed by a major quarrel, and then a breakup. Even though you were literally both sensei, you ignored each other as much as possible, but only until one day.

The Hokage was fed up with this, so he sent you and Kakashi and his squad on a joint mission. The squad walked on, talking and laughing, while you ignored each other.