The silhouette of the quill in Hermione’s hand quivered as she traced delicate letters on Luna’s collarbone. It was past midnight and the lights were out in the library. A wand glowed feebly, wedged between two books. Hermione finished the line of black ink by its light and inspected her neat handwriting with satisfaction.
“Abeo,” she said. The writing vanished, fading into Luna’s skin.
“It tickles,” Luna said. She lay, relaxed and dreamy as ever, among the stacks of books on Hermione’s favorite studying table.
“Yes,” Hermione said, half to herself. “Interesting side effect of the spell. Maybe we could improve it with a bit of experimentation.”
“I like it,” Luna said. She unbuttoned three more of her shirt buttons, her hands bumping into Hermione’s. Her skin was pale enough to almost resemble paper in the wand's light. Hermione, her quill still resting on Luna’s skin, found herself staring.
“Did you—did you manage to get off all the text from before?” she said.
“Oh yes, it was easy,” Luna said. “It worked perfectly. I learned two whole chapters of the History of Chinese Magic in the Han Dynasty in just one hour sitting in the bath.” Her eyes took on a slightly distant expression. “The counter-charm tingled a bit.” She shifted on the table, stretching, and her shirt fell open further. “Well? Are you going to keep writing? I’d like to learn three chapters tomorrow.”
Not meeting Luna’s gaze, Hermione let the quill drift over her skin again. The use of tea leaves in healing potions dates back to the Warring States Period, she wrote. The end of the sentence, its letters growing progressively shakier, climbed up the curve of Luna’s breast.
“You should come study with me in the bath sometime,” Luna said vaguely.
Hermione’s hand slipped, the tip of the quill scraping over tender skin, and Luna gasped. Hermione froze, wincing. Her eyes flicked up.
“Sorry,” she said, licking her lips, “I made a mistake.”
“No. No mistake,” Luna said.
Hermione looked back down at the smudged words. An image flashed through her mind of Luna sitting in a tub, covered in handwriting, Hermione’s handwriting all over her naked body, and Luna’s fingers tracing the letters, wandering all over her breasts and stomach and further down—
A slight gasp escaped her lips. Before she could think twice, she licked her thumb and swiped at the smeared ink on Luna’s skin, brushing against the swell of a breast. Luna's back arched the barest amount and Hermione glanced up to find her lips had parted, the corners curved up slightly.
With an unmistakable gleam of mischief in her eyes, Luna unbuttoned her shirt all the way.
Two could work mischief. Hermione flipped the quill and dragged the feathered end down between Luna’s breasts, leaving traces of ink.
“Oh,” Luna said, squirming. “That tickles.”
“Abeo,” Hermione said.
Luna squirmed again.
“I’ll never finish if you can’t hold still,” Hermione said, taking the opportunity to throw a leg over Luna’s hips, straddling her firmly. “I’m going to need a lot of space,” she said. “Three chapters might cover every. inch. of. you.” She punctuated each word with a touch of a finger down Luna’s stomach, stopping at her navel. Their eyes met, sealing a silent agreement.
"Well," Luna said, "studying can be hard work sometimes."
"But that's no reason to be less than thorough."
Luckily, Hermione Granger was a very good student.