Saving face.
Example: if you ghost your teacher without quitting that's inconsiderate, and calling it "saving face" is saving face.
Otherwise you get some weird conflict where they need to tell a teacher, which I think is automatically a superior?, that they're no longer required. So they're in a position where they need to 'criticize' a superior, and it looks like they choose to do so obliquely, and then just freeze when said superior asks them to tell it straight.
But how is ghosting saving face then? Wouldn't telling the teacher that the teacher is amazing, but for different reasons they can't have any more lessons be saving face?