Conversational

John peers into Sherlock's room, checking in on him. He can see only a detective-shaped lump on the bed, blankets stretched over Sherlock's head. John murmurs softly, "Sherlock?"

The blanket shifts where, presumably, Sherlock's hand stretches in response.
"Awake?"
"No."
"Good."
The aforementioned hand appears from under the edge of the blanket, reaching toward John, making grabby motions.
"Sher?"
"C'mere."
"What?"
"Lie w'me."
"...Sherlock. That's not something flatmates -"
"Sod social conventions."
"Wh- They exist for -"
"They exist t'make best friends feel ashamed in the privacy of their own flat. Come here John."

John hesitates a moment, and then sighs. Of course Sherlock is right. Sherlock is always right. And anyway what's a cuddle between best friends? John shuffles closer, but he stops at the edge of the bed. It's hard to shake the feeling that he's not supposed to do this. Not supposed to want this. He feels horribly awkward and a little sad.

But of course, Sherlock Holmes hasn't been one to follow social conventions since he was very small, and even then, did he really? So he stretches, his protective blanket pulling away as he reaches and grabs John by the wrist, giving him a good yank.

"Sher!"
"C'mere."
"Wh- It's - Just wait a second Sherlock, Christ, let me -"
"Hmfh. Settle."
"Ufh...Hmh - Ok...Wait. No not yet Sherlock I said wait."
"God's sake John."
"Well I could just g-oh!"
There's a mix of grunts from both men as Sherlock tugs John into position, to lie on his back almost in the center of the bed.
"There. Properly settled. You're welcome."

And Sherlock winds himself around John's side, settling his head on the manhandled man's chest. After a moment, he nuzzles deeper into John's jumper, and John sighs and finds the edge of the blanket to pull it back up over Sherlock's head, with a soft mutter of, "I hope you suffocate under there."

The only response to that is a satisfied, sleepy hum as Sherlock settles back into a comfy doze.