John supposes there isn't a specific time for this experience. Ever since day one, Angelo has always assumed John and Sherlock are together.
Like the first time, whenever they walk through the door, Angelo's face lights up and he seats them at the table near the window (if it is open at that time) and insists on getting a candle because 'it's more romantic'.
No matter how many times John has corrected Angelo, he completely ignores John or talks over him like he isn't even speaking. It's a bit annoying really, if Angelo wasn't such a nice guy with fantastic food, he may have stopped going there. But when John can't get Sherlock to agree on any kind of food, Angelo's is the best place he can get Sherlock to eat. It's a sacrifice really, suffer under the assumption by all the employees that he is gay, so his best friend doesn't starve himself.
One night John couldn't get Sherlock to agree on anything for dinner and finally suggested Angelo's, which Sherlock accepted with a huff, John smirked slightly knowing full-well that Sherlock wouldn't turn down Angelo's, he never does.
Per usual, they arrive and greet Angelo with a smile, he seats them at the available table by the window and scurries off for the candle. He doesn't even say he is going to retrieve it anymore, he just does—but John still gives hopeless attempts at explaining they are not a couple.
The candle is lit, flickering between the two of them. The contrast of the orange flame on Sherlock's black, blue and white features is an interesting contrast and John noticed the way Sherlock's eyes twinkle every time he looks at John through the flame.
Angelo brings them their drinks, and puts in their order when Sherlock states 'the usual.'
The night goes as it normally does. Sherlock and John talk about everything there is to know and absolutely nothing all at once, because this is Sherlock and he can tell you about the world or simply say nothing, and John will know he is just deducing the couple next to their table.
It's amazing really, the way Sherlock works, and the way John can work with him. Like magnets, the two of them move with each other, one moves and so does the other. Never drifting apart but never coming completely together.
John would never think of the two of them in this way, John sees them as close friends and nothing more. Close friends who happen to live together, bicker like a married couple, have joint bank accounts, work together, and save each other in more ways than one.
No, they are nothing more than friends and John does not see how they can be misread for anything else.