Luna Lovegood had never known why her parents named her "Luna". In her seventh year, she finally decided to ask her father. Xenophillius Lovegood sat her daughter down and began to tell her the story.
Xenophillius and Amestris Lovegood had only been married for a year when the passion had fizzled out of their love life. Desperate to rekindle their marriage, both Xeno and Amestris had spike their evening tea with Passion Potions, which, when separate, worked wonders, but when mixed, had a rather unfavorable side effect.
Xeno and Amestris nearly tore the house apart in their wild sex frenzy. They moved on to the garden, where they both ended up completely naked, covered in dirt, and where they passed out.
Amestris woke up around midnight, bathed in moonlight, and woke up her husband. Neither of them could remember anything about that evening except that the moon had never looked more beautiful.
Nine months later, Amestris gave birth to a little girl, named Luna.
Xenophillius finished his story with "You're named Luna because you were conceived under the full moon."
Luna Lovegood now wishes she had never asked.