Mycroft doesn't have OCD, he merely makes everything perfectly so Sherlock's mind can be quiet.
When Sherlock and Mycroft met others when Sherlock was 5 or something, and entered the real world instead of their isolation as young children, Sherlock could not handle the information. There was far too much of it, and it was loud in his ears, he couldn't focus on anything else and Sherlock took to saying most of the things he saw, and alienated him from others by doing so.
When they return home, Mycroft made everything spotless, particularly in his room, so Sherlock's mind was at ease. When Sherlock had nightmares of the loud deductions and the fact that no-one else saw them save for Mycroft, he would go into Mycroft's room and curled up beside him and everything was quiet. Mycroft's 'OCD' was for Sherlock.
Then one day, before Sherlock goes east for his missions, Sherlock slips into Mycroft's home and curls up beside him, and Mycroft comforts him. Sherlock leaves before dawn, and they never speak of it again.
Can be platonic brotherly fluff or Holmescest, I do not mind. :)
On Mycroft's 'OCD'
When Sherlock and Mycroft met others when Sherlock was 5 or something, and entered the real world instead of their isolation as young children, Sherlock could not handle the information. There was far too much of it, and it was loud in his ears, he couldn't focus on anything else and Sherlock took to saying most of the things he saw, and alienated him from others by doing so.
When they return home, Mycroft made everything spotless, particularly in his room, so Sherlock's mind was at ease. When Sherlock had nightmares of the loud deductions and the fact that no-one else saw them save for Mycroft, he would go into Mycroft's room and curled up beside him and everything was quiet. Mycroft's 'OCD' was for Sherlock.
Then one day, before Sherlock goes east for his missions, Sherlock slips into Mycroft's home and curls up beside him, and Mycroft comforts him. Sherlock leaves before dawn, and they never speak of it again.
Can be platonic brotherly fluff or Holmescest, I do not mind. :)