About how Mycroft missed his Sunday morning jog

Set just after The sign of Three. Sherlock comes back home, expecting a long and lonely night. But someone's waiting for him at Baker Street. "Oh for God's sake! What are you doing here!" "Ah, finally. Cinderella's coming home before midnight. How was the ball?" "WHY ARE YOU HERE!" "Nice to see you too, brother mine." Sweet moment between the bros. Mycroft's first person POV.