Sherlock would argue that he probably has looked more ridiculous than in that moment, and probably, quite frankly, will again in future, but ideally John isn't going to see any of those. Unless, perhaps, he wants to. Unless it would make him happy. As long as the laughter is shared, as it is now.

It so often isn't. Almost never, and Sherlock has come to the opinion that it's even worse to be simply ridiculous than it is to be worthless. Worthless people get no regard. Ridiculous people get less than that. Still, he can bear a bit of it, if it isn't unkind. Perhaps.

In that light it's easy to smile away John's little giggle (itself an amusing sound, really).

“All right,” Sherlock agrees. And in they go.

The air is heavy, quiet, and there's a fine layer of dust on all of the surfaces. Easily enough removed, with the right spell. These piles of books, though...

Sherlock crosses to the centre of the room and picks one up from the top of the pile, tilting it to read the title. Old edition of a third-year transfiguration text. Boring. Not even any interesting doodles in the margins. Sherlock grunts softly and tosses it unceremoniously towards one corner of the room. His 'neatening' process really isn't, but it makes up for its inefficacy with its volume.