This was requested by ILoveFandomGuys I hope it is kind of what you wanted?... Even if it isn't I hope you enjoy it anyway.
----------------------------------------------

It was a crisp autumn morning and the streets of London were littered with frost-covered golden leaves. As you stared lucidly out of the coffee shop window -hot chocolate in hand- you smiled as cars and smiling faces went past. You love a smiling face.
"(Y/n)?....(y/n)??"
"Wh-wha?" You said, snapping out of your daze with a jerk, spilling hot chocolate down your knitted turtleneck. You scowled, irritated, as John laughed at you, making a pathetic attempt to wipe your front with a napkin.
"Thanks John!" You stated, sarcastically as you put the mug down on the mahogany surface.
You smiled at him, it was nice to catch up with John. He was one of your closest friends but he is usually out with Sherlock so you never really have the time to just chat...
"So, how's the baby?" You smiled
"Sherlock's fine" he replied, giggling
"I meant Rosie but go on" you giggled too.
"Well, he spends a lot of time with Mycroft nowadays"
"Mycroft...? He's the brother right? Sorry I don't really know him that well. We should meet up some time!"
John raised his eyebrows as he methodically tapped his fingers on the wooden table. Immediately, you realised something was amiss.
"Yeah... Probably not the best idea" he muttered solemnly
"Why not?"
"Well." He started "I've seen your blog, you are probably the happiest person on the planet! Mycroft is- Mycroft is- ummm... Unusual, let's say"
You were intrigued now, you could feel your pupils expanding with curiosity as you childishly shuffled your chair closer to John. The chair legs screeched like a falcon as they battled with the floor.
"Unusual?" You pried
"Yes. He doesn't show emotion like a normal human being. I don't think I have ever once seen that man smile" You furrowed your brow, slightly upset at this news. How can someone not smile?...
Suddenly, you sprung up from the table and grabbed your blogging laptop. Throwing a handful of coins at John for the drink, you pelted out of the shop shouting I've your shoulder "sorry John! Got to find Sherlock! I will make his brother smile if it's the last thing I do!".

- time skip -

You were sat cross legged in the waiting room of Mycroft's office waiting for him to finish an -according to Sherlock- 'ever so important video conference with North Korea'. You admired the decor. Hundred-year-old portraits of dukes and duchesses with serious expressions lined every wall and the blue ish gold wallpaper brought an overwhelming sense of regality to the proceedings. Sherlock was pacing around the small room, complaining (as always)
"I cold be working right now you know (y/n)? Someone could be dead right now and I'm here, missing all the fun, waiting for you to meet my irritating, fat older brother so you can make a futile attempt at making him smile!"
You shook your head, dismissing his comment when, out of nowhere, the pair of double doors leading to his office cracked at the lock and swung open, allowing light to spill into the waiting room from his huge, stained glass window.
"Can I go now?" Sherlock sulked like a child as he lightly kicked the furniture.
"If you must" you whispered nervously at him as you (for the first time) made eye contact with Mycroft. The first thing you noticed was his style. His pressed, pin-striped suit fitted impeccably, clinging to his seemingly rather lean body in all the right places. His eyes were steely and lifeless which contrasted with the light, freckled and almost teenage-boyishness of his skin. The next thing that drew your attention were his perfect, straight lips... John was right. They looked as if they had never curved in his lifetime. You could have lined a spirit level up with his grimace and the little bubble would not have moved a millimetre.
"What are you here for?" Mycroft asked with a refined tone of voice which made you shudder and blush ever so slightly.
"I... I'm... Uh. I have a blog sir and I wanted to do a piece on family... (You lied unconvincingly) Could I maybe ask you some questions about Sherlock?"
Mycroft drew in a long, meaningful breath and you blushed again as you saw his masculine, suited chest expand and contract as he did so.
"I'm free until lunch so I suppose... Yes that would be possible"
You went to thank him, when he spoke again interrupting you "and please, call me Mycroft"
You noticed his hands fidget slightly as he invited you into his office. He almost appeared as nervous as you were.

You started by asking about Sherlock and his parents which seemed to provide no change in his facial expressions whatsoever. This all changed, however, when you asked about love interests.
"Have you ever had a partner Mr Holmes" you asked casually as you leaned against the windowsill of the grand office. He swallowed and his eyes darted around the room, frantically looking for a way to avoid the question. Alas, he was in too deep.
"No." He stated plainly. Despite his calm, collected exterior Mycroft was boiling inside.
"Would you ever consider having a girlfriend?" You pressed further.
He was beginning to panic now. Your (h/c) hair and cute face were beginning to give him heart palpitations and tiny, tiny beads of perspiration started to form in his forehead.
"Are you alright Mycroft?..." You investigated as you studied his face with great detail. For one, brief, explosive moment, your lines of vision interlocked and Mycroft was vulnerable. It was then that you saw it...

His mouth didn't budge a single inch...

But his eyes did...

His steely, cold eyes shone, twinkling like a coil of Christmas lights and his eyebrows raised ever so slightly with joy. Stars appeared in his eyes, changing them from two empty voids into two gaping galaxies, twisting and blinking in time with the universe. Mycroft suddenly looked away and his cheeked flushed a plush, pink colour, causing him to look at the floor, embarrassed. Your own eyes widened and you grinned stupidly with excitement and triumph.
"Well... Mycroft. I'd best be going. Thank you for your time."
You bit your lip and without looking back, you skipped out of his office like a child with their first crush.

As soon as you got home, you threw your laptop onto your kitchen table and opened it as if you expected it to be a lost pirate chest laden with diamonds and gold. You moved your fingers swiftly and elegantly across the old keyboard as you typed, biting the tip of your tongue between your teeth as you grinned with hopeless romanticism. As soon as you were finished and posted, you leaned back on your chair and covered your eyes with your aching hands.
"Now all I have to do is wait..." You said to yourself aloud as you stated into the ceiling, unable to get the image of Mycroft's face out of your head.

Over at 221b Baker Street, Sherlock's laptop made a 'ping' as the notification came through that you updated your blog. Excitedly, John reached for the computer before Sherlock grabbed his wrist.
"Hey!!" John spluttered
"My laptop, my rules" Sherlock stated as he lifted it up off dusty armchair and began to read aloud what you had written...

"Today, I may the most intriguing man I have ever encountered in my life. He dresses smart, he has a good job, he only has one problem... His friends say he never smiles.

This man, however, is not the cold hearted robot that his reputation exposes him to be. This man loves his family. And I know he smiles... I've seen it.

You see, this man does not smile in the conventional way, oh no... This man has a gift so much better. He smiles with his eyes... And his eyes tell me everything I need to know"

"How touching" came a low, genuinely moved voice from the doorway.
"Mycroft!" John spoke excitedly, "you heard all that right?"
"Every word..."
He looked down at his polished shoes and his eyes twinkled one more
"I think I've fallen for her John..."
"Eww..."
"Shut up Sherlock." Mycroft spat
John rose from the sofa and approached the taller man. He looked him in the eye and nodded his head ever so slightly. Mycroft knew exactly what to do.

Twenty minutes later, you heard a knock on your door. Not a confident knock. Just three, short, quiet taps with the brass knocker. The person on the other side of the wood was clearly nervous. You meandered down your short hallway and twisted the key in the lock. It made a most satisfying click as the metallic mechanism aligned and you turned the worn handle to reveal the skittish visitor.
"Hello. I believe you wrote a blog about me?"
You eyes widened and you brought you elegant fingers across your mouth to (badly) hide your shock at seeing him at your doorstep.
"I did? Oh, yes, I did... Silly me" you laughed nervously, inviting him inside.
You stood in an awkward silence for a moment. It was like you were both submerged in water and the background noise was muffled and magnified creating both an eerie stillness and a feeling of instability simultaneously.
"Mycroft I-" you began but he cut you off. He grabbed your waist, gracefully swung you around and allowed you to tip your head backwards as you lips came into contact with each other. Your hair fell back from your shoulders and your eyes fluttered closed. After a blissful five seconds, Mycroft brought you back to your feet and after catching sight of your face, shocked by his spontaneity, he panicked
"Bad?" He fretted
"Not bad. The antithesis of bad" you grinned as you slid your hand round the back of his head and kissed him again. More passionately this time, falling into his arms as you knew what you were doing.
"Okay... That seemed good" Mycroft stated as his eyes glittered vividly, scanning your face.
"Better than good" you reassured him.
"Do... You want some tea?" You asked, laughing awkwardly, realising that your weight was still fully supported by Mycroft as you only had one foot on the ground. Mycroft sensed this and, once again, brought you upright.
"Actually I fancy coffee... If you wanted to, you could come out and get some with me?..."
Your eyes widened with joy
"Are you asking me on a date Mycroft Holmes?"
"I suppose I am."
You nodded profusely and hugged his tall frame. As you embraced, Mycroft spoke quietly to himself.
"Well, well, well... Who would have thought I'd end up in the same situation as my dear brother?... Falling for his blogger..."

----------------------------------------------
A/n - GAHH! Sorry this is so long and cringey! I have no idea if this is actually anything like you wanted but I've written it now so.... Yeah.

Peace out 👌🏻