Notes:
I think Sherlock, John and Mary are great together as they are - John and Mary as a couple and Sherlock as their friend - and I'm sure Sherlock is pretty happy with this situation because he wouldn't be interested in anything else anyway.
But just because something is a little out of character, doesn't mean, that it's not fun to read and write these stories anyway...
My stories are a like public television: they fade out when things get serious...
Story:
Mary had always liked to startle people. To make them uncomfortable without doing anything that she could be blamed for, because it were the people who had a problem with what they had just witnessed and not she who had done something tedious.
They weren't aggressively open about their arrangement, but they didn't keep it a secret either. They acted like other people did around their spouses, just that they sometimes had two of those at their side or - when just two of them went somewhere - the other people often knew, that there was a third person in the picture.
It was very seldom that they had to answer any curious questions or comments, because nobody dared to ask or say something, although of course everybody had heard rumors.
Mary was pretty sure that everybody died to know more and she sometimes was tempted to ask Mycroft to install a bug in the break room of the practice she worked in and John did his locum work, or in Scotland Yard's offices just to hear the speculations that went on there.
She saw the looks when Sherlock sat in the waiting room and waited for John and her to go to lunch together.
She realised how Greg set his eyes nervously to the ceiling when John and Sherlock sat in his office reporting after a night of observations and she came stormed in and dropped a cranky not-yet-dressed kid and a pile of toddler-clothes, diapers and two glasses of puréed pears in Sherlock's lap proclaiming that he had been supposed to be at Baker Street half an hour ago because it was his bloody turn take Rosie to daycare and she had the hell to go to work now. Then she yelled at John, that he could at least have reminded Sherlock, when the two of them could hardly have been too occupied to remember their kid, when they had just been sitting around in a car the whole night. Or had they found enough things to get distracted by even without her? Even though she was angry as a hornet she kissed both her men goodbye and stormed out again.
She realized the sudden silence when she and John consulted with each other what to get Sherlock for christmas while sitting in the break room at work. Mary looked up at all the prying faces that stared at them. "You know, there isn't exactly a social convention about if you are supposed to each get a present for your mutual boyfriend or if we can get him something together", she explained to all of them, since they all seemed to be so damn interested. And suddenly nobody was interested anymore and they all looked somewhere else and desperately searched for a completely different topic to talk about.
John was very angry with her afterwards. "Was that really necessary?" he asked.
"I thought we agreed that we aren't embarrassed about our relationship?" Mary answered. "Or is it relationships?"
"The grammar hardly matters now, don't you think?" John snapped. "I just think, you don't need to rub it in everybody's face."
"I don't rub it in everybody's face. We were having a private conversation and they all were eavesdropping. They had it coming!"
John had basically nothing to add to that.
John honestly wasn't embarrassed about their ménage a trois. They were honest with each other, they loved each other. This wasn't like cheating or having an affaire, so what was there to be embarrassed about? That was how he felt about it for himself and around Mary and Sherlock.
But contrary to Mary he wasn't amused by the reaction of his surroundings. After he had found out about Mary's past, he had to admit that Sherlock was right: even though he hadn't even known about it at that time, her dark history had been what attracted him in the first place. But even though he knew that he liked unconventional people and an unconventional life, he still didn't like that he liked it. And while Sherlock had never tried to appear to be normal and Mary had to act normal in recent years to not attract attention, John wanted at least appear normal to the outside, even if he had accepted that he and the life and people he loved weren't normal at all.
He would love to meet people and present them to his beautiful wife and daughter and go on with the conversation. By now even introducing a male partner lead to smiling nods of approval and not to critical frowns anymore. But introducing both at the same time killed every conversation before it had even started.
Anyway it seemed that he would have to live with that from now on, if he didn't want to hide this part of his life.
Sherlock again had a completely different approach.
Contrary to what he liked people to think, he didn't totally give a shit about what people thought of him. He didn't put much afford into his public image, but if he had a choice he wanted to be thought of as eccentric - which he succeeded with pretty well. That was why he hadn't exactly been offended by the things the papers had written about his - imaginary - sex-life with Janine: that stuff had been quirky enough to emphasise his extravagance reputation. And a relationship with two people at once - let alone one man and one woman - was certainly kinky enough to do the same. As he didn't like and see the point with publicity he didn't deliberately push his private life into the public, but he didn't work on being particularly discreet either. Partly because he didn't get the severity of it. While Mary was very much aware how scandalous all of this was considered by most people and liked to play with their reactions, he knew, that this was pretty unusual but he didn't have a clue just how severely unusual it was.
To him the whole concept of a close and longterm relationship had seemed utterly absurd up to now anyway. Compared to the absurdity of having such a relationship in the first place the question if it included two or three people didn't play such a big roll anymore.
He was aware of course that most other people considered a relationship with one person normal but since he had spend the rest of his life startling people with pointing out his disinterest and the general unnecessity of any romantic relationship, it didn't seem that different to him to now startle people with having one partner too many instead of one too little.
