It's Ginny

Ginny comes into view startling Luna into hopping lightly causing a sudden burst of pleasure and her eyes to roll back slightly.

Ginny seeing this giggles and pouts while saying, "Oh Luna, why didn't you invite me for this fun?"

Luna recovers from her surprise and says, "Sorry, I was going to invite you for some fun on the second day of break."

Ginny smirks and says, "Good thing it's past midnight then, huh?"

Luna trembles, realising what Ginny is about to do.