Author's Note: This is post Poppies, a few years later. I recommend you go back and read the supporting story to truly appreciate the fluff. :) And the story was inspired by a drawing I found on Tumblr, post/18381156515.
-Also, the Mary in this story is based on the Mary originated in Poppies, which I wrote long before series 3 premiered. So she is different than the real Mary in the canon.
Part-time Fatherhood
John wailed from his spot on the chair. Sherlock stared intently at him, his brows furrowing and the corners of his mouth turning down with frustration. What was wrong with him? Sherlock asked himself. He glanced up to see Poppy, her head resting in her hands and her wide blue-eyes watching intently.
Sherlock sighed and asked, "What's wrong with him?" he looked down at his former flatmate's squalling son, feeling annoyed and frustrated. Babies would be so much easier if they could simply state what they needed, instead of having the same reaction for every problem. He ran down the list John senior had given him before rushing off for a vacation with Mary.
"Remember, no cases while we're gone. Mrs. Hudson and Lestrade will make sure of that. No guns, no experiments. Make sure John is fed, burped, slept, clean-"
Sherlock paused. Clean. He hesitantly leaned slowly closer towards John's flailing legs. He quickly jerked back when the strong scent of fecal matter reached his nose. He looked to the stairs but Mrs. Hudson had gone to the market and John wouldn't stop crying till he was changed.
"Stop worrying, John." Mary had said, pulling her husband towards the stairs. "He'll have Poppy, who will help Uncle Sherlock, won't you darling?"
"Yes, Mama!" Poppy said, beaming up at her adopted uncle.
Much to everyone's surprise, Sherlock and Poppy had become rather close. Probably because she didn't speak too much, and found watching Sherlock stare at a microscope for hours at a time endlessly fascinating. Sherlock, as he had promised, had been teaching Poppy the science of deduction and the art of observation. While she didn't take to it as quickly as Sherlock or Mycroft had, she was coming along nicely. Sherlock was rather proud of her, though he would never admit it.
Sherlock looked up at Poppy, "Do you know how to change him?" Poppy nodded eagerly and pushed her poppy red hair out of her face. She ran to the bag and brought Sherlock a fresh diaper and wipes. She guided Sherlock through changing John, and though the diaper was barely hanging on and the snaps on the pyjamas weren't perfectly aligned, they were successful. Had Sherlock stopped to pause and observe the fact he was taking guidance from a four-year-old, he may have been less proud in his achievement.
But John was still crying.
Clean? Check. Fed? Check. Burped? Check. Slept? It was his own fault, he kept waking up every 4 hours, Sherlock thought. It was a good thing Sherlock didn't sleep much. Sherlock couldn't figure out how John had made it through his days, though it would explain his zombie-like demeanor the past few weeks, and the ubiquitous cup of coffee in his hands.
Sherlock scratched his scalp, mussing his hair. He had only agreed to take on the children because Harry had fallen out at the last minute. Everyone had been rather hesitant to let him have the job, but Sherlock had stated that if he could take down Moriarty, the mysteries of child caring would be easy. Now he was wondering if he was wrong.
"You have to hold him." Poppy said, standing at Sherlock's shoulder as he was crouched in front of the chair. Sherlock looked back to John. Even with Poppy, Sherlock had never been very good at holding small children. He preferred it when he wasn't responsible for making sure their heads didn't flop around.
"Here" Poppy seemed to understand what Sherlock was thinking, even without him saying. She grabbed his thumb and pulled him over to his chair. He sat down in the chair and Poppy expertly picked up her brother, bringing him to Sherlock. She handed him John and then arranged Sherlock's arms so that he was holding John in a semi-relaxed position. She smiled then ran away, obviously moving onto something else.
John stopped fussing when his mouth found the sleeve of his striped footie pyjama. Sherlock watched the tiny John contentedly gnaw on the fabric and marveled at how much he looked like his father. Poppy looked more like her mother, but John was almost an exact replica of his father, right down to the ashy blond hair, blue eyes, and simple smile. Sherlock hesitantly ran a long finger down the slope of John's nose, as he had seen Mrs. Hudson do with both John and Poppy. Suddenly those blue eyes noticed Sherlock's fingers and the sleeve was forgotten.
John grasped Sherlock's long fingers and laughed as if it was the funniest thing he had ever seen. Sherlock had long known that fatherhood was a road he would never walk down. But, he admitted quietly inside himself, there was something pleasant about this. About holding a tiny life in your arms and feeling protective, proud…happy.
Suddenly, John started fussing again and the pleasant feeling popped. Sherlock frowned again. Poppy quickly returned to the room, a ridiculous stuffed pony in her arms. She held the pony out to Sherlock, who looked at it questioningly. She almost rolled her eyes at him, and tucked the animal in the crook of Sherlock's arm, next to John's head. The familiar scent of the animal comforted him and John drifted off into sleep.
Poppy clambered up in Sherlock's lap, her purple corduroy jumper making funny noises as she settled herself in the crook of Sherlock's other arm. She rested her head on his shoulder and shut her eyes as well. Sherlock looked between the two children in his arms. Their faces were surprisingly similar when completely relaxed with sleep; their mouths open forming small O's. There was something soothing about the two sleeping children, with their slow synchronized breath. The feeling was similar to the calm that came with the opiates Sherlock used to take, but it was better. It was softer, more wholesome. Sherlock blinked a few times, his eyelids feeling heavy, till they closed and Sherlock slept.
Mrs. Hudson walked up the stairs to the flat, bags of groceries in her hands. "Sherlock? Poppy?" she called, walking into the flat. Then she spotted the sleeping trio and a large smile came over her face. She set the bags down on the floor and tiptoed closer, pulling out the phone John had lent her. She found the camera and snapped a photo, without managing to wake them up.
"How do you think Sherlock's managing with the kids?" Mary asked, looking over to John.
"He has Mrs. Hudson and Poppy there, so I think, well, hope, that he'll be fine." His phone buzzed with a message, he opened it and a smile spread across his face. "I think we may have underestimated him." He passed the phone to Mary with the picture of the sleeping Sherlock and kids. She smiled. "They're in capable hands."