SHERLOCK
Everyone was irritated, or vexed, or saddened, or anxious by being deduced. But not John. Never John.
Normally, John was clearly thrilled whenever Sherlock turned his deducing skills on him, and exuded an air of both challenge and expectation which was so uniquely John.
But now, John was uncomfortable, for God's sake!
So: John was allowing him to discover what was going on, if he could, but in fact wasn't willing to share, and even truly hoped that Sherlock wouldn't find it (whatever it was) out. Which meant John indeed still cared, if he gave him a chance to bring out into the light something he would prefer staying in the dark; but which made no sense, because why would John try to hide something from him if it wasn't BAD anyway? And which only made Sherlock even more worried, and even more intent on uncovering John's now just acknowledged damn secret.
And the more Sherlock tried to get inside his head, the more John felt obviously more and more uncomfortable.
His eyes were often escaping Sherlock's gaze, even though they always returned (again, a proof of John's good will). There was an odd glint in them, despite the still undeniably recognisable concern, and the pupils were dilating (the day was nearing its end) a bit too fast — he should get John to have his eyes checked, just in case.
John was shifting and fidgeting on his chair. His breathing was somehow accelerating — was it fear? — and his cheeks were somehow flushed — was it shame? — It was frustrating, to see all those details and be unable to make sense out of them!
And then, it clicked.
No way!
Not John. Please, not John!
But, when you have eliminated the impossible, whatever remains, however improbable, must be the truth, right? Sherlock couldn't tell if his brain had worked it out from recognition from his past or from a last new hint from John he had unconsciously noted, but he knew.
And, for the first time in his life, Sherlock wished he was wrong.
He desperately went to grasp John's wrist, willing that last clue to undermine his certainty, but John's arms swiftly retreated before he could get a hold of one of them — an admission in itself; as final a proof as if he had actually taken John's pulse.
JOHN
Sherlock in his deducing limbo couldn't care less about tea and his mug stayed untouched, but John was taking now and then a few sips from his own: it gave him some countenance, right?
It quickly turned truly surreal though, because it looked exactly like his dream from a week ago, them sitting here in silence. Worse, it felt like it too, because John was discovering, now that he was willing himself to take his guards down, that he was indeed having in reality the same tingling reaction as in his dream. And the more intense Sherlock's gaze turned while analysing him, the more John got self-conscious. And the more John got self-conscious, the more Sherlock's gaze intensified. Ever heard of a vicious circle? The atmosphere turned suffocating.
John could pinpoint the exact moment when Sherlock's brain had done the math. He would have been able to do so even without the gasped "No way!" that escaped Sherlock's lips, because Sherlock suddenly turned livid. And that was definitely a sight John had never seen; and one he wished he would never have to see again, because the ghastly look on Sherlock's face felt more destructive than actually being wrapped in Semtex or having a gun pointed to his own head.
Sherlock's right hand moved towards his hands, and John promptly hid them out of reach, under the table, feeling more exposed and more ashamed than he had ever been. What had he done! He shouldn't have let Sherlock discover this…