Plausible Deniability

by Iwantthatcoat

Kink meme prompt:"Mycroft would sometimes use his little brother for experiments. At first,"innocent" but some turned a bit inappropriate and sexual? This might have resulted in Sherlock's aversion to sex and Mycroft has a lot of guilt, hence his overprotection." This is non con holmescest (not the "nice" kind),as well as explorations of asexuality and abuse and how they intersect.

2. Experiment

Mycroft dumped the coloured water out of the glasses and into the sink, frowning as the contents landed with a loud splat.

"Really, Daddy. One would think he would be smarter than that."

"It's not about intelligence, Mycroft, it's about experience. He doesn't understand mass, or volume, or area. It's too abstract a concept right now. His brain can't perceive it yet."

"How old was I? When I could get it right?"

He sighed. "It isn't about getting it right. Conservation experiments are about how you preserve something in your mind...preserve its essence...even as its form changes. You have to be able to see that the liquid itself doesn't change when it moves to a taller glass. To him, its being in the new glass makes it a new thing, not an old thing with a new shape."

"But it's happening right in front of him. He doesn't have to remember anything."

"He has to make the connection between the liquid in the old glass and the liquid in the new one. It's as if he is remembering what the liquid looks like in the old glass and recognising it in the new one as the same thing."

Mycroft was still disappointed. He expected his brother to grasp things quickly. At least be ahead of any "theoretical children".

His father smiled. "It's nice to see you have such faith in your brother's skills, but it is supposed to happen between 5 and 7 years old. Two is a bit young. Even if he doesn't get it until next year, or the year after, he will still be ahead of the curve. It's not really something you can teach him. You just have to wait for his brain to develop."

"How old was I when I understood it?"

"I don't think we ever really tested that sort of thing. Four, maybe?"

Mycroft frowned. Clearly they weren't taking this parenting thing very seriously. How could they not have collected any data? How would he know where he himself stood in comparison to others? At least he could be counted on to monitor his brother's progress.

He picked up some modelling clay from his mother's studio and showed Sherlock two balls that were approximately the same size, asking him if they were so. Sherlock nodded. He placed them down on the table, then took one and rolled it between his hands until it was a long, thin snake and put it down beside the ball.

"Now, does one have more clay, or are they the same?"he asked.

Sherlock pointed to the snake.

Mycroft shook his head, while Sherlock wiggled the clay snake and made hissing noises.