It was their anniversary.
Two years of marriage.
They had gone to a fancy expensive resturant that you had to get a reservation for a year in advance (unless you were Moriarty).
They had gotten drunk on expensive wine, but you couldn't really tell.
They strolled down the street, heading back to their flat hand-in-hand, and Seb was content. He knew Jim would never submit to such a mundane and obvious thing if he was sober. Seb takes what he can get. Jim was humming 'staying alive' under his breath. Sebastian smiled.
As they walked, the CCTV cameras turned to watch them, but he didn't care. He felt a tug on his arm and glanced back. Jim had stopped and was looking at Sebastian seriously.
"You need to learn the waltz." Seb smiled turned to face him. Jim pulled Seb's hand onto his shoulder and put his hand on Seb's waist. They clasped their free hands together.
"Why now?"
"What if I have to meet a client at a formal function and you can't dance? You represent the Moriarty empire. I can't have you looking ignorant and brutish."
"Of course, darling." Sebastian drawled, lifting Jim's hand to his mouth. He looked down into Jim's dark eyes as he kissed his fingers tenderly. Jim blushed, which was probably the alcohol but Sebastian enjoyed it nonetheless.
"Follow me," Jim instructed.
"Yeah boss."
Sebastian had never danced before, but he was a quick learner. Soon they were swaying in step under a street lamp. Jim started up humming again and Sebastian chuckled. "I don't think 'Staying Alive' has the right beat for the waltz."
"Improvise, darling," Jim sighed happily, leaning against Seb.
"Why do I have to be the girl?" Jim made a frustrated sound.
"Because you're so freakishly tall." Seb's mouth twitched upwards. He dipped down and kissed Jim's forehead, mumbling, "Not my fault you're so freakishly short." Jim turned his head up to glare and Sebastian kissed him. Jim tilted his chin up to reach his husband's lips and growled angrily when he had to push himself up onto the tips of his toes. Sebastian smiled, amused, into Jim's mouth and he pulled away to pout.
"I will skin you, and make you into shoes."
"Not on our anniversary, dear. Besides, who would make those shoes with me gone?" Jim snorted and rested his head against Sebastian's chest. After a few moments of quiet peace, Sebastian murmured "Love you." Jim smiled into Sebastian's chest.
"Love you too."
They danced for a while longer into the night under the dim light of the streetlamps.
Mycroft steepled his fingers together, watching the video end for the nth time.
Looks like even Moriarty had a weak point.