A/N: Warning for references to abuse.
Sherlock had never really noticed before. When he did nearly pulled out a lock of hair at how he should have. He prided himself on knowing the smallest of details, yet he never saw the ones Mycroft displayed frequently. Sure, he tried to hide them. But they where both Holmeses, and nothing gets past a Holmes.
It was the little things.
A flinch when Sherlock would stand up suddenly. The way he stood on the opposite side of the room when they went to stay at their old home with Mummy. How he would never sit near their old dead father's chair, or go into his study, or read the books he had kept. Mycroft did everything in his power to avoid anything father was closely associated with.
Eventually Sherlock realized what it meant.
The final clue that had pushed him onto the epiphany was when Mycroft came once again to meddle in his brother's affairs.
Sherlock was hunched over his violin, contemplating how he could reconstruct it into a guitar using no additional materials, when he heard footsteps coming up the stairs. They hesitated at the door and sherlock called out bitterly "Go away Mycroft."
The man outside the door sighed and let himself in. He strode in and stood in front of Sherlock, who didn't condescend to even glance up.
"You got yourself in a lot of trouble this last case."
The younger Holmes didn't reply.
"Mummy is upset." Sherlock whipped his head up to glare, snapping "Why should I care what she thinks? I don't need her approval." Mycroft watched him and he bristled under the quiet sadness and pity in his brother's eyes. Sherlock's eyes glinted and he added on maliciously, "I wonder what Father would think of you now, Mycroft." Their dad had never liked Mycroft. He had always claimed to be dissapointed in him and that Sherlock was his favorite.
Mycroft froze in place, something flashing in his eyes that he quickly smothered before Sherlock could decipher it. He turned around, and Sherlock stared at his brother's back, brow furrowed in confusion at the unexpected response.
"Just be careful." Mycroft's voice was flat and he left the flat, leaving a perplexed Sherlock to his mystery. Sherlock's eyes narrowed and he leaned back in his chair, steepling his fingers, and the violin lay ignored in his lap.
Mycroft was sitting at his desk, reviewing paperwork about a new treaty between two countires when his phone buzzed on the table. He glanced over and picked up, looking to see what it was now.
I didn't know. -SH
I didn't want you to. -MH