Remember that one time when Sherlock was dead and John was miserable, so he quickly got engaged to that woman who turned out to be an assassin, so he dumped her, but first he grew that hideous mustache that no one liked?
Yeah, well, SOMEONE did.
And someone wanted to try it.
But someone was worried that their...crush wouldn't like it.
So someone didn't try it.
But then, years later, someone wasn't able to see their husband (yes. Crush became husband) for a few weeks (WEEKS! Six of them! Not even a weekend together!). (Something about Egyptian Politics and nuclear warheads.)
Someone got lonely.
And someone's husband wasn't there to see it anyway.
So someone grew a mustache.
And Sherlock laughed.
And John smiled.
And Gregory hated it.
Just like Mycroft knew he would
