Disclaimer: JKR owns. Bow before my inherently witty disclaimer.
Author's Note: This is a response to the 100 Quills challenge on LiveJournal—I claimed Ariana Dumbledore, obviously. Haha, I am totally insane.
Ariana looked up at her elder brother with wide eyes, the soft, silky fabric of the nightgown she held in her hands bunching together. "Mine, Al? Mine?"
Albus turned around from where he had been half-facing the stove and rolled his eyes to the ceiling. Ariana decided that he did that a lot. "No, Ari," he drawled, "it's mine."
She shrugged and tossed it into the laundry basket beside his trousers; Albus' face became horrified.
"Of course it isn't mine!" he snapped. Ariana, instead of whimpering from the irritation in his eyes, drew up to her full height (which was still considerably shorter than Al, however), and glared at him.
"I was being sarcastic," Albus told her, turning back to the stove and the simmering sauce that was cooking there. "Sarcastic is when you say things and mean the opposite." Ariana frowned and flung the nightgown—which was actually very pretty, in her opinion—beside her own pile of clothes in the basket.
"Stupid," she muttered to herself. She flicked her fingers sharply against Albus' neck as she walked past him. She didn't feel bad about it. After all, what kind of person said things they didn't mean?
Maybe it was some grown-up thing.