Ponies do not serve Princesses. It is the Princesses who have to serve the populace. It is their job. It is the law!
Luna’s reservations and lack of consent is not relevant. She must perform her duty because the law must be obeyed. Refusing to please ponies with her mouth would be a criminal act punishable by another banishment to the moon.
This story is written for children between the ages of 5 and 10 who struggle with public speaking.
This story penetrated and entered Imposing Sovereigns IV, using the prompt Unorthodoxy.