Prompt: Mycroft caring for Sherlock. Not in a romantic way, but a brotherly way. Can be any age of them 3
"Mycroft darling, can you come here a moment," a soft voice called from the drawing room. Placing his book down Mycroft made his way to the drawing room to find his mother cradling the latest edition to the family. "Will you hold Sherlock for me, dear? Mummy has to take care of a few things."
Mycroft sighed. He hadn't been left alone with the new baby yet but he didn't exactly like him already. Perhaps it was just the fact he was use to being on his own. Reluctantly nodding he made his way to the large arm chair in the corner. Mummy always made him sit down whilst holding Sherlock so he thought it best to do it straight away.
"Oh you are such a good boy," his mother smiled. Once Mycroft was sitting down she gently passed Sherlock over so he was resting in Mycroft's arms. "Now he's asleep right now but remember you have to look after him for Mummy. Promise me?"
"I promise, Mummy," he replied. He didn't like to let Mummy down.
"Thank you, dear," she called out as she made her way out of the room. Leaving Mycroft alone with the baby.
He seemed bigger than Mycroft remembered. The hair had appeared to have grown too, producing little ringlets at the end. He didn't look like Mycroft. So many things were different. Then there was the noise he made. Mycroft was told he was a quiet baby. One that slept and ate like he was meant to. Sherlock however kept him up in the middle of the night by screaming his head off. "You're not like me at all, are you?"
Sherlock scrunched his nose and began squirming in Mycroft's arms. He never did that as far as Mycroft was aware. Staring down at the tiny face Mycroft was unsure what to do. Carefully he raised the hand, which wasn't holding Sherlock's head, up took hold of one of Sherlock's hands. "Hush, please don't wake up."
For some reason that seemed to work. Though Mycroft's little finger appeared to be in a death grip between tiny fingers. "It's weird having a little brother," Mycroft said. He didn't know why he was talking. It wasn't like Sherlock would be able to understand him. "That's what you are. My little brother. I'm seven right now but you're just tiny."
The grip on his finger tighten as little Sherlock let out a yawn. Mycroft smiled. Perhaps the baby wasn't so bad after all. He wasn't going to attack him. Wasn't going to ruin anything that already existed. He still had his parents. There was no difference expect an additional person in the house. So what if he lost some sleep? Or some of his mother's attention was taken away because of the baby? It was just a baby. One that looked so tiny and vulnerable. Why hadn't he noticed that before?
Then it dawned on him. Sherlock was always going to be tiny and vulnerable next to him. He was always going to be younger and in danger. People always fought for the little ones. He knew that from his stories. Britain and Belgium. Knights protecting ladies. Brothers helping brothers. He didn't know what was going to happen in the future. How could he? He was only seven. He didn't know what was going to happen to him. What was going to happen to Sherlock. Yet he knew one thing. He could try and be there. Big brothers were meant to be responsible weren't they? That's what Mummy had told him before Sherlock was born. A soft smile spread across Mycroft's face as he continued to watch Sherlock sleep. "I will always look after you. I promise."