Disclaimer: This story is based on characters and story from BBC and Arthur Conan Doyle. No money is being made and no copyright or trademark infringement is intended.
Prompt: Sherlock's thoughts on Mycroft leaving him and starting school.
Mycroft never knew that the starting of his tenth year in school would upset his little brother so much. It started out small at first; Sherlock would throw his usual fits, which all ended in sulking in a locked room, but the problem grew worse when Sherlock started tampering with Mycroft's belongings. School books were vandalized in artful ways, sweaters were mysteriously torn in the laundry, and even his umbrella was found with several gaping holes cut in it.
It wasn't until Sherlock was confronted that it dawned on Mycroft that his little brother might have missed him.
"Don't be ridiculous, Mycroft. I don't miss you. I'm merely suggesting that I should be the one progressing into a higher education than being stuck among the cretinous creatures in my primary school."
But Mycroft could see through Sherlock's lies. In the end, Mycroft forced his little brother into an awkward and unwilling hug that Sherlock soon ended by pushing his brother away in disgust.
The next morning, a new umbrella was found waiting for Mycroft, leaning against his bedroom door with his school things.