At a party earlier today, Sherlock told Mycroft that one of the men he was talking to is having an affair and the other wets the bed. Mycroft called him bad words in front of everyone. (Why did he get so mad? He used to be proud when I deduced people!) After they came home, Mummy spanked Sherlock and sent him to his room, but he sneaked back out to hear Mummy and Mycroft talking. If he'd stayed in his room, he might not have heard Mycroft say that he wished he were an only child. Sherlock ran back to his room sobbing. Mummy tried to talk to him, but he wouldn't let her in.
As the boy plans to run away from home, he hears Mummy shouting, and Mummy never shouts. Sherlock knows he'll get in trouble for spying, but his curiosity gets the better of him and he creeps to the edge of the balcony again.
Mummy yells, "I can't believe my son said such horrible things! After everything we've been through over the last two years, I would think that you'd know the importance of family! What Sherlock did was wrong, but your behaviour today is inexcusable!"
Sherlock's greatest fear is that Mummy might someday be this angry at him.