Title: A Heart's Length Away
Summary: "You're going to leave me."
Pairing: Sherlock/John
Rating: PG
Word Count: ~360
Notes: Written with Imogen Heap's 'Half Life' in mind and playing in the background.

They're in the sitting room: the curtains are drawn; the fire kindles lowly while the TV murmurs quietly about a program neither of them are interested in. To anyone, it would seem almost romantic, cosy – two people sharing a quiet Sunday night in before the rush of the week starts again.

With anyone else, they'd be right.

As it is, Sherlock is resting with his back to John's chest, while John is tucked up into the corner of the couch. It's a comfortable arrangement. But John's shoulders are stuff, his spine straight and the fingers he has in Sherlock's hair haven't moved for nearly thirteen minutes.

He's thinking. It's not uncommon, despite what Sherlock might believe but even less rare are his thoughts. He's known – he's always known – but it doesn't make it any easier. He tries not to think about it, not too often – perhaps once or twice a month, and it's usually in moments like these when Sherlock lets him in, when his mind quiets and they can just be. He knows Sherlock knows it, too – knows that John thinks about it at these times. Maybe that's why he does it – just to make John think, to remind him.

And part of him hates Sherlock for it, while another part just simply cannot stand the possibility of not doing this anymore.

Sherlock shifts and John compensates but draws his fingers from Sherlock's hair and settles them on the top of his own thigh. He closes his eyes and ducks his head against the back of Sherlock's neck, his lips skimming against the line of skin between hair and collar. Sherlock cants his head and John exhales, brushing his nose and he can almost imagine Sherlock's tiny smile.

He inhales – all Sherlock – and exhales quickly tilting so his forehead rests on the juncture between shoulder and neck.

"You're going to leave me."

Sherlock doesn't shift, doesn't react to John's non-question. He merely inhales once and turns his head slightly to glance at John from the corner of his eye.

"Yes." John can feel the other man's jaw moving slightly – he's licking his lips. "Will it hurt?"

John squeezes his eyes shut tighter and breathes out.

"It already does."