Disclaimer: I don't own Sherlock. Obviously.

Mycroft Holmes was sitting in a chair, at a desk, trying to get homework done. His little brother, however, was making this rather difficult, for the boy was sitting on the chair with Mycroft, legs thrown over one of the armrests and back leaning against Mycroft's back, as he was turned to face the desk.

"Sherlock, could you read somewhere else?" Mycroft sighed at last.

"I could," Sherlock said, still absorbed in his book, then looked up and grinned mischievously. "But I won't."

Mycroft sighed, but chose not to argue over such a childish matter, rolling his eyes and going back to the letter he was writing.

"Mycroft, what does 'solivagant' mean?" Sherlock asked suddenly.

"It means 'wandering alone.'"

"Oh." He paused and murmured "That's like me. I'm solivagant."

"No, you're sitting here, bothering me. You're a nedovtipa," Mycroft corrected.

"What's that mean?" Sherlock asked, head tilting to the side in curiosity.

"Look it up in the dictionary," Mycroft replied. He moved so his back was leaning against the back of the chair and Sherlock's head fell into his lap.

"You are a dictionary," Sherlock countered, looking up at him. Mycroft rolled his eyes and said "It means a person who cannot take a hint."

"And you're boring," Sherlock complained. The boy paused, frowning, before looking up at Mycroft curiously. "When did you become so boring, Mycroft? You used to be fun."

"I didn't get boring, Sherlock..."

"Yes you did," Sherlock interrupted.

"...I grew up," he finished, ignoring his comment. Sherlock placed his open book on his stomach and thought.

"Then I never want to grow up. I'll be interesting forever," he declared.

"You're ten, Sherlock," Mycroft said. "You'll have to grow up eventually. And growing up doesn't mean getting boring."

"Says who?" Sherlock said indignantly, crossing his arms over his chest and frowning. "You're not the boss of me."

"Yes, I am," Mycroft said, looking back at his document. "I'm older and therefore have authority over you."

"Keep trying to convince yourself of that, dear brother," Sherlock said with a smirk. He got up, forgetting about the book. He left it on the floor and ruffled Mycroft's ginger hair instead. "You're only seventeen.."

"Mm." Mycroft said ignored him. Sherlock draped his arms around Mycroft's shoulders and peered at the essay he was trying to write in disgust.

"Don't get too boring, okay, Myc?" He said and flicked the back of Mycroft's head before picking up his book and wandering off. A fleeting smile graced Mycroft's lips at the use of his old childhood nickname and he murmured "Yes, Sherlock." But he knew the boy couldn't hear him.

I wrote this a while ago, but posted today because HEY! GUESS WHO TURNED SEVENTEEN TODAY?

It's me. I turned seventeen today. (Happy birthday to me.)