Look at Sherlock’s concentration on John’s eyes. He doesn’t blink once and doesn’t dare remove his gaze because he doesn’t know the next time their faces will be that close, if ever again. This. This gives him an excuse to look so deeply into John’s eyes at such a close range. He knows John isn’t pulling Sherlock in to kiss him, but I’m almost sure as hell he damn well imagined it.
It makes me kinda sad that most of the pre-season 4 theories and a lot of the meta you come up with sounds so much better than what season 4 actually was :/