so in LOTR’s appendices it says that legolas eventually builds a boat and takes gimli across the seas and into the west, the gray havens. you know, the place arwen isn’t allowed to go because she’s in love with a human dude bUT LEGOLAS (AKA ‘YOU LITTLE SHIT’) JUST SAYS “FUCK IT” AND SNEAKS GIMLI INTO THE GODDAMN UNDYING LANDS LIKE CONTRABAND TWIZZLERS INTO A MOVIE THEATER
WAITING FOR THE BUS TOOK A PICTURE OF ANOTHER BUS WAITING FOR THE BUS IN THE RAIN I’VE BEEN WAITING FOR THE BUS AS THE SUN CAME UP BUT THE SUN AIN’T OUT NO MORE CAUSE IT’S GREY WAITING FOR THE BUS THERE’S A GREY ONE BLUE ONE A RED ONE ALL OF THEM TURNED AWAY I’VE BEEN WAITING FOR THE BUS GOTTA CATCH A BUS GOTTA WATCH NEWS GOTTA REGIMENT A PLAN FOR THE DAY
So he may not even have that nickname in Sherlock. Sherlock did ask him in TSoT if he had an ‘international reputation’, to which John responded, “No, I don’t have an international reputation.” But he was drunk. So who really knows?
The blog doesn’t specify gender.
I feel the need to add this bit of information, which can be found here.
This fan-created nickname has its origins in the Sir Arthur Conan Doyle novel The Sign of Four, in which Doctor Watson boasts “an experience of women which extends over many nations and three separate continents.”
Further details of the good doctor’s lady-killing history are never discussed, making it unclear whether he is simply an unapologetic whore or whether he has had many brief and ill-fated past marriages. Regardless, one can be reasonably assured (given the rather characteristic Victorian stiffness of vocabulary) that Doctor Watson had more than made the acquaintance of aforementioned women.
In fandom, this moniker is most often referred to in fanfiction (a notable culprit being Atlin Merrick) and is used as a testament to John Watson’s sexual experience, which generally goes hand-in hand with sexual prowess.
"Now, Watson, the fair sex is your department." —Sherlock Holmes (it isn’t *his* department, mind you)