Children dislike John. Children love Sherlock. This really did shock John, considering John's a far better caretaker than his partner. It all makes sense, though. Kids like calm people, and for the most part Sherlock is far more calm than John.
This did hurt John's feelings a little bit. Last summer when Harry had a baby, Sherlock and John went to visit when Harry got home.
Sherlock wasn't very interested. He asked weird questions which caused everyone to just stare at him until he shut up and sat in the corner.
An hour and a half later, the baby was crying and nobody knew how to stop her; she wasn't hungry, she didn't need to be changed, she wouldn't go to sleep. Finally, after an hour, Sherlock stood and shouted, "Oh, for God's sakes!", took the baby from Harry and rocked her to sleep.
Everyone stared. Rightfully so. Sherlock doesn't like human contact, adult human contact, you can imagine the shock when they all saw him rock a newborn to sleep.
"What?" he snapped.
Everyone's eyes were still round and probably dry for not blinking, assuming once they blink the whole dream sequence will go away.
"Oh, it's not that hard, really. All of you people that a thousand nervous ticks that babies recognize. Good luck with that, Harry." Sherlock smirked, caressing the baby's head.
Harry stared from Sherlock to John. John stared at Sherlock.
"Oh, stop. Really. I'm good with kids."
"But you're-"
"So?"
John swallowed. His heart was leaping out of his chest. This man, this magnificent man that can't function talking to a group of adults from Scotland Yard is cradling a newborn, rocking her back and forth while she soundly sleeps after an hour and a half of fighting everyone around her. This baby was stubborn, as is her mother, but this man…John's just in disbelief.
"Stop gaping at me, John. I have two nephews. They were babies once."
John wished and longed for that to be their daughter, for Sherlock to be caressing the head and blanket of their own baby that had Sherlock's black curls and John's blue eyes. Impossible? Of course. But more impossible than either of them actually getting pregnant is John convincing Sherlock to adopt.
"Can we not have this conversation now, John?"
"Wh-what conversation?"
"You have drool on your chin and you're staring at me and a baby. We'll talk about this later."
Harry stared at John. "I still can't-you, Sherlock." Harry looked at Sherlock, "Gay, ex-junkie that chases criminals and uses nicotine patches in substitute of rest or caffeine, holding my baby, that I couldn't get to sleep, that Doctor-I-Invaded-Afghanistan-Watson couldn't get to sleep, that I probably won't be able to get back to sleep ever again! You're never leaving, got it? You're staying with me now."
"What? No! Take her back!" Sherlock made to give the baby back, but John intercepted her and cradled her. In seconds, the baby shot awake and wailed hard and loud.
"Ok, ok, take her back!" John shouted, handing the baby back to Sherlock. She calmed instantly.
"Why are you being weird, John? Are you jealous that babies like me?"
"Yes!"
"Oh, I didn't think asking you was that easy."
"Yes, I am jealous! I'm a doctor and you're a sociopath!"
"You're tense, especially now. Of course she doesn't want you to hold her, I can feel the anxious waves radiating off of you."
John and Sherlock stayed at Harry's for the next six hours. Finally, Harry said she understood what Sherlock meant and they were allowed to leave. They didn't speak the whole way home, but when they got up to 221B, Sherlock took his shots.
"Ok, I realize you're both jealous that you suck at taking care of babies and you're angry because I can't and won't give you children, but you can't be angry with me. At least not for the first. That is your doing. Actually, they both are. You fell in love with me."
"I know, Sherlock, and God help me I will never fall out of love with you, even if I try. But it does hurt, and you need to understand that."
"Which one?"
"Well, both. But the second one. It's like you-"
"Taunted you with it?"
"Yes." John's face drooped into a very sad frown. He rubbed his eyes in frustration at himself. It wasn't Sherlock's fault. They've had this conversation.
"I love you, John. And I'm very sorry. I just couldn't do it."
"I know, I know. I love you, too. I'm sorry."
They hugged tight for a few minutes, then Sherlock spoke. "John?"
"Yes, love?"
"Where's Gladstone?"
"Oh, fuck!" John ran out of the apartment faster than Sherlock's ever seen. As it turns out, John forgot at the dog at the 'dog-sitter' from before he went to work this morning until now, which has been almost 18 hours. Sherlock chuckled, ok, he laughed. When John got back he wasn't amused. He held the dog close to him and whispered he was sorry, and when Sherlock laughed he'd snap a quick, "Shut the hell up."