Please be sure you've read Boy, the previous drabble, before this one, and then follow it up with Beneficial.
Hamish shuddered. He loved Father, he really did, but sometimes it was impossible to live with him. He heard heavy footfalls on the stairs and resisted the urge to bolt into his room and lock the door. Steady, even, solid. Dad then, not Father.
"Hey, Hal." John groaned, lowering himself onto the ground next to his son. "I'm sorry you had to hear that."
He sniffed, a feeble attempt at masking his prior crying jag. "You have nothing to be sorry for, it's him."
"Your father means well." This comment was met with a derisive snort, so similar to Sherlock's that it caused a pang in John's chest. "He's only human. He tends to expect more of you than he should, but that's only because he loves you, and he knows how smart you are. He's just never been very good at expressing his emotions, so when we don't live up to his rather absurd expectations, he lashes out. He wants to apologise though, why don't you come downstairs?"
Hamish rubbed his red, blotchy face and stood up, following John back downstairs. Sherlock was standing in the doorway, looking suitably contrite.
"Hamish… I'm sorry. I was irritated, and I said some very inappropriate things. I treasure you and your dad, and I didn't mean to make you feel unintelligent or belittled."