Rosie was about to turn 3 years old.

Her vocabulary had exploded in the last year, she was becoming a master at walking, and she even took the stairs by herself while altering her feet. She really started to understand her routine and schedule and she loved sharing her toys with John and his friends. She was beginning to understand and empathize with others and their emotions, and she loved to pretend.

John had worked hard to develop a stable home and routine for his daughter. He worked at the clinic throughout the week and would keep his crime solving with Sherlock to the weekends, unless there was a particularly pressing need for his involvement in a case in the evenings. Even then, he limited those outings to only once a week.

Sherlock had made many sacrifices for his friend and his goddaughter. Changing old routines and habits was difficult, and he now had to learn to be much more responsible and organized with his lab equipment. John had fought with him regularly about him not bringing body parts home, and eventually, Sherlock conceded that he would only work on experiments involving body parts at the morgue. Sherlock and John worked hard to baby proof the flat, setting up baby gates and locks to prevent Rosie from getting into evidence or gruesome case files. It was a difficult adjustment for Sherlock, but he worried for Rosie's safety as much as John did, so he did whatever he could to help out.

One afternoon, a cool, October rain was pattering on the windows of Baker Street. Rosie had fallen asleep curled up in John's chair; he placed a blanket over her and then walked into the kitchen to speak to Sherlock, still dressed in his pajamas, studying a slide under his microscope.

"Hey Sherlock, I wanted to talk to you about something."

Sherlock didn't look away from the slide, "Yes?"

"I think we're going to have to consider getting another flat…" John rested his hands on the counter across from Sherlock. At his comment, Sherlock looked up at John with a look of surprise that John could tell he was trying to mask.

"You and Rosie? You'd like to move out?" He spoke low, but confidently. John could tell that the detective was trying not to show his hurt or confusion, but John could read him well and was quick to correct the misunderstanding.

"No, us. All three of us. I know we've talked about it before, but it really bothers me that you sleep on the couch all the time. It's not good for your back and shoulders."

Sherlock's face relaxed and he went back to looking at his microscope.

"John, you know that I do not require the same amount of sleep that the average human being does. It really is not an inconvenience for me."

"Yeah, but I would really feel better knowing that you had your own space to escape to if you're ever… I don't know, sick of Rosie or me? And don't pull that 'its just transport' card with me. I know better. You've been looking haggard lately and I know it's because the couch is not that comfortable."

Sherlock sighed and looked up at John, "John, I really do not grow tired of you or Rosie. If it really bothers you, perhaps we can invest in a pullout couch or futon of some sort."

John shook his head, turning now to grab the kettle and mugs and start some tea.

"No. Sherlock, I'm serious. You can't sleep on the couch forever and you need your own space. You're an adult."

Sherlock began cleaning up his things.

"Why does it matter to you? Why does it bother you so much?" Sherlock asked.

John turned back to him.

"Because you're my friend. And you've made a lot of sacrifices around here for me and for Rosie and I want to make sure that you're being taken care of, too."

Sherlock scowled. They had been practically whispering through the majority of the conversation until now. Sherlock responded, in his full baritone voice, "You don't have to worry about me. I'm fine."

In the living room, Sherlock and John both heard Rosie shift and heave a sigh in her sleep.

"Shhh, I don't want our daughter to wake up to us fighting. She missed a morning nap today and I know she needs the rest." John insisted.

Sherlock's whole body froze as he was adjusting something on his microscope. In a quieter tone, he said, "Say that again."

John looked back at Sherlock and saw that Sherlock was staring at a spot on the table and his brow was furrowed.

"What? I didn't want Rosie to wake up. She missed her morning nap." He obediently obliged.

"No, no, no." Sherlock shook his head, but didn't look away from the table. "You said, 'our daughter'. You said you didn't want our daughter to wake up to us fighting."

John heard his point instantly and bit his tongue and looked down at the table as well. I'm not replacing you, he told Mary in his head. No one could ever replace you. It just slipped out. I'm sorry. Rosie will always be just yours and mine. Inside his head though, Mary had a big grin on her face and was chuckling, relax, she said, I think it's sweet. And true. He's as much of her father as you are.

"-ohn?" Sherlock's slightly concerned tone and higher volume drew John out of his head.

"Sorry. You were saying?" John opened his eyes, but turned to the kettle to finish the tea.

"Our daughter."

John sighed. He turned back to Sherlock and spoke, looking him right in the eye.

"Yes of course, 'our daughter'. She's as much yours and she is mine. You take care of her just as much as I have and you do love her. I know you'd hate to admit that, but it's true. And you've done so much for us, for her, that she is. She's ours. Your just as much of her father as I am."

Sherlock was frozen. After a few moments, he said, "I don't understand. She's not biologically my daughter and I could never replace Mary. I am not a woman nor am I-"

John cut him off.

"No, you idiot. I know that. No one could ever replace Mary. And I'm not asking to be in a relationship with you. Christ! Can you imagine the publicity?" He chuckled to himself before continuing, in a much more serious tone.

"Sherlock, you once implied, in front of your brother, I might add, that you considered me to be a part of your family. Well, we consider you a part of ours as well. Rosie definitely does. I mean, think about it, she calls you 'Papa' and I know you know that means 'dad'."

Sherlock's frozen posture melted a little as he considered John's words.

"Yes, I've actually been concerned that she's been calling me Papa lately. I don't know where she got the name. I thought 'uncle' might be more appropriate. I didn't want to upset you."

"Why would it upset me?" John asked as he turned back to the tea to finish preparing the mugs before they went cold.

"Well, I know how you so adamantly deny that we are a couple and I'm sure that as Rosie gets older it will be confusing for her friends and maybe even her to understand the nature of our relationship, especially if she's calling me 'papa'. I worry that others will get the wrong idea about us."

John smirked and slid Sherlock's mug of tea to him.

"Sherlock, people are going to talk and think what they want to think. It doesn't matter to me anymore. I just want Rosie to be well taken care of and loved. Also, what was it that Mrs. Hudson said when we first moved in, 'Oh there's all sorts round here! Mrs. Turner next door has got married ones.'" He did his best to impersonate Mrs. Hudson's high pitched voice, "Who cares now a days what kind of relationship we have? By the time Rosie is in school, it will be perfectly normal for her to have two dads and no one will think much of it."

Sherlock huffed in response as he blew on his tea before sipping it.

"Speaking of, what would we do about Mrs. Hudson if we moved?" Sherlock added.

John leaned against the counter and thought. After a moment he responded, "Well, I know she'll be heartbroken. But we do need a bigger space. Of course we'll come and visit her often. I worry though, about her health and her being alone."

"Indeed…"

"So it's settled then? We'll be looking for a house or another flat?" John asked.

"Yes. I believe that Rosie should have a larger space to occupy to play. 'Three's a crowd' here in Baker Street." Sherlock replied.

"Alright."

Just then, a loud rumble of thunder rolled outside and woke Rosie, who was now sitting up and crying in her chair. John set his tea down in a flash and in a moment was at her side comforting her in the living room.

Sherlock watched and glanced around the flat. He couldn't believe that soon, they'd be living somewhere else. He conceded that it was the right choice, but the memories that this place filled him with were many, both good and bad. He thought maybe a fresh start in a new place would be better for both he and John. They could build new and better memories in a new place.

Sherlock also took a moment to consider John's statement about how he was just as much of a father to Rosie as he was. Parenthood, fatherhood, was not an adventure that he'd planned on taking in his life. His life now was so domestic. But, truth be told, he did love Rosie. For once, he could honestly say that he loved his life. There was something about her curiosity and watching her learn new things that intrigued him. He was suddenly reminded of a comment he made years earlier on that first night, "I'm not a psychopath, I'm a high-functioning sociopath…"

He realized now, after all he'd been through, he couldn't have been more wrong.