It's well known that Sherlock Holmes is not one to make friends. And while most of the time he seems indifferent to it, there are rare moments where his loneliness is noticeable.
Specifically when all the friends he does have, are dancing around him. Without him.
It's the day of Mary and John's wedding. It was a bit chaotic, but that's to be expected when you invite Sherlock Holmes as a best man. But now the chaos of the day subsided, leaving a peacefully happy moment. Everyone has just seen Mary and John's first dance as husband and wife, and now everyone is happily dancing.
Sherlock is looking for someone to dance, too. But when he looks around he sees Mary and John dancing together, Mrs. Hudson, Molly and Lestrade have all found a partner.. and even Janine, who Sherlock admitted his love for dancing to, had found someone else.
He was about to leave, until someone caught his eye.
It's not any news that you're a wallflower. You're a relative of Mary, but you barely make appearances at family events like this.
And today you lean against a wall of the room, watching everyone else dance. But then you see Sherlock looking at you. You'd seen him standing by Mary and John moments before. They seemed like an ineffable trio. But as always with trio's, one is left behind.
The dissapointment and defeat in Sherlock's expression is palpable. But you know someone like Sherlock Holmes would never admit it... Sherlock approaches you, holding out a hand. "Will you dance with me?"