It had been years since you’d last seen Mycroft Holmes, but there he was. Talking to some important man you’d forgotten the name of. The ballroom was nicely decorated, the chandelier reflecting light across the room. The last time you’d seen a chandelier so nice was at a ball hosted by the Holmes family in your youth. 

You were standing off to the side, watching Sherlock try to teach Beatrice how to dance, and watching them both awkwardly flail around with their poor motor skills. The adults were dancing beautifully, but you were too young to join in. “Don’t envy them, you’ll have to dance a lot more when you’re older,” you hear a familiar voice behind you. Sherlock’s older brother, Mycroft. It was foolish, really, the crush you had on the teenager. You were only a year older than your best friend, Sherlock, but you were slightly infatuated with his brother Mycroft. You knew it was illogical, he was far too old for you… at least for now. 

His piercing blue eyes looked at you as if you were a child that lacked understanding of the world. You admitted to yourself it must be true, because Mycroft was so much wiser. “Perhaps, but it’s not fair. Why can’t I dance now?” you continue, trying to reason with Mycroft. He looked over at the swirling dresses of the women, and how the chandelier made the colours more mesmerising. Mycroft sighed, looking down at you. “Come on,” he said before turning around. You follow, curious as to what his proposition was. You two went to the back terrace, where you could just barely hear the music. He offered this hand to you, “May I have this dance?”

Mycroft was patient, a saint even. He guided you through the steps to the dances you didn’t know. He knew that you would become a Holmes one day, it was inevitable. Additionally, you would have better luck at teaching Sherlock how to properly dance than anyone else. You felt your face flush as he calmly explained things to you. You could listen to his voice forever, just happy to be in his orbit. Unfortunately, the moment ended as soon as it started, when Silas found you both and asked you to come back inside. You and Sherlock then spent the rest of the night watching Mycroft talk to other partygoers his age from the stairs. You treasured that evening.

Now here you were, twelve years later, seeing the same piercing blue eyes across the room, silently willing him to look up and see you. You hadn’t seen Mycroft since Beatrice’s funeral. You and Sherlock had written, until one day he just stopped responding, so you stopped writing. You fiddle with the jewelry around your neck that was caught on your partlet. When another man asked you to dance with him, you did. You let your fan dangle off your glove as you danced with him. You remembered the feeling of the first time you danced this way - with Mycroft Holmes himself. 

Meanwhile, Mycroft had noticed you, your dress shimmering under the light. He didn’t believe that you were the same child that had once been shy and would linger with Sherlock, judging everyone. When the song ended, he steeled himself, and walked over to you. He stood the same way he did twelve years ago and asked, “May I have this dance?”

You quietly agree, and the two of you take to dancing. “You’ve grown up,” he says cautiously, testing the waters. “As have you,” you say as he spins you. “How’s Sherlock?” you ask. Mycroft felt a tinge of guilt, knowing it was partially his fault that you no longer knew his brother. It was selfish, and something Mycroft had locked away in the back of his mind. “He’s fine, he fancies himself a sort of detective,” Mycroft says lightheartedly. He didn’t want to think of his separating you from Sherlock. 

No, Mycroft had kept tabs on you, from a distance. Despite this being the first time you’d seen him since the funeral of his sister, this wasn’t his first time seeing you. A few years ago he’d caught a glimpse of you. He knew your family wanted to marry you off, and he also knew that your father - for who knows what reason - liked you with Sherlock. Mycroft told himself that it was just a great coincidence that Sherlock’s crimes had landed him in prison, but it wasn’t that simple. Mycroft could’ve gotten Sherlock out of it, or allowed Sherlock to get letters, or told Sherlock that you were still writing to him, unaware of Sherlock’s arrest. He let Sherlock think you had moved on with your life, hoping desperately that you had by now. Perhaps you would be married when he ran into you next, forever closing the door on whatever possibility of you ever becoming a Holmes was.

You hum noncommittally at Mycroft’s statement. “And you? What do you do now?” you inquire politely. “I work in Her Majesty’s Foreign Office,” Mycroft says, downplaying his role. “I always knew you’d be someone great,” you say before you can stop yourself. You pretend not to notice the blush creeping up Mycroft’s neck as he looks past you, trying to ignore the compliment. “What about you? How have you been?” he asks you, deferring. “I’ve been perfectly fine,” you say indifferently. “You should call on Appleton some time, I know my mother would be happy to see you,” his invite does pique your attention. “She’s back at Appleton?” you question him. “Yes, she’s been discharged,” he pauses before continuing, “there’s a lot you should know.” 

“Such as?” you ask him curiously. He felt enamored by your gaze on him, seeing you view him as interesting. Yet, he stepped back when the song ended, coming back to reality. “Come to Appleton with me next Monday, and I’ll explain everything, I just…” Mycroft trailed off before finally saying, “I must go.”

This also goes for if you're a cis guy who likes being/dressing feminine or a cis girl who likes being/dressing masculine.