After they got married, Sherlock randomly starts introducing John and/or himself with a double name, despite the fact that they both decided to just keep their names as they are. John, obviously, doesn’t say anything against it, in fact he loves the little proud face that Sherlock makes each time he gets to introduce himself as “Sherlock Watson-Holmes”, but - and it takes John a little while to notice it - at times Sherlock exchanges the two last names and makes it a “Holmes-Watson”.
At first John can’t quite make sense of these very randomly occuring changes, nor can he place the almost gleeful smirk accompanying Sherlock’s name being mentioned first other than as Sherlock’s usual, occasional hubris.
That is, until the realisation what the decisive factor is hits John unexpectedly at their next crime scene, and he pulls Sherlock aside, not sure if he should rather be angry or burst out in a giggle fit.
“Sherlock, you cock, stop doing that!”
“I don’t know what you’re talking-”
“Don’t you even try. Just… stop switching the names.”
“John, as you might remember, we didn’t agree on having a shared name, so neither of these two options is exactly false-”
But John cuts him off by pulling him dangerously close, which makes Sherlock startle for a moment, and drops his voice as he continues:
“But I, for my part, do not want the entire Yard to eventually figure out that it’s code for ‘who of us topped last night’, so I suggest you drop it or I’ll make sure there won’t be a Mr Holmes-Watson for a very long time.”
