AN: The thesis is over, the finals are over, I'm done with my master's, and am a grad student now. Yay me!

That means updating again, though other kinds of duties have piled up while I was studying, so I still can't promise any kind of regularity, unfortunately.

Mycroft's fears have been fulfilled and exceeded by that dinner with Sherlock.

Somewhat detachedly, he wondered if Sherlock would have acted this way if he though Mae was his real girlfriend, too. He also wondered if he wanted to know the answer.

His brother seemed to have two purposes for the evening: to embarrass him as much as possible by trying to name as many of his weaknesses as he could, and to flirt with Mae to the best of his ability.

There was no real reason for Mycroft to worry about either. Mae already knew his biggest weakness, and this wasn't a real relationship, so he had no reason to be jealous.

That didn't mean he wasn't irritated. Very irritated, in fact.

Just as he felt he was going to explode and make a scene – Sherlock's intention, undoubtedly – Mae reached over the table and lightly touched his hand.

It calmed him immediately, which in turn caused him some worry, though completely unrelated.

It made sense, he supposed, that an unexpected touch would jar him, shake him out of his anger and help to ground him. But shouldn't he be more alarmed by any touch at all, considering it was not something he normally did?

He turned the thought in his head and realized that no, he shouldn't, because he had been used to Mae touching him – and quite more intimately than this – for quite some time. In a way his light touch had been more personal than all of their sexual encounters, but still, he was used to letting her in his personal space.

Satisfied with this explanation, he turned his attention back to the conversation.

Watching Sherlock from the corner of his eye, he realized the precise moment when he started to think that he was winning.

He knew Mycroft wasn't really romantically involved, so he couldn't exactly steal her from him, but making her genuinely interested in him while she dated Mycroft solely for information's sake would probably be considered a good substitute of that.

Mae had been at her most charming the whole evening, and he could see why Sherlock would get the impression that this was going well.

Mycroft didn't want this plan to succeed on principle, but wasn't quite sure what Mae's view was. Obviously she was far too rational to be really charmed, but she might want to enjoy a bit of fun, not knowing that nothing would ever come of it, because of Irene Adler.

He shot her a look and realized that she recognized the smug signs too. She cocked an eyebrow at him, and he could read 'I'll deal with it' in her eyes.

So he set back, prepared to enjoy the show.

"You're very charming, Mr. Holmes," she said sweetly. "Why, by your manners, one would almost think you were French."

Mycroft had to fight a smirk as Sherlock smiled dazzlingly in response. "Well, I'd hate to be accused of that, but one can learn from one's neighbours now and then."

"Oh, that's certainly true. Though I think one must be very careful what one learns, sorting the good from the bad. By the way, would you say you learned much from Mycroft?"

"Not really. He never had much time for me. I'm mostly, as much as I detest the phrase, a self-made man."

This was such a blatant lie Mycroft had to fight to stay calm.

"A pity."

"Oh, I wouldn't say so. I'm sure he would have done more damage than good."

"Well, I'm quite certain you wouldn't have quite these...manners...had your brother had more influence over you."

"See? As I said, damage."

"Indeed."

As the diner progressed, Sherlock started to catch on. He could read facial expressions well, and neither Mycroft nor Mae were trying to keep a complete poker face, so he knew there was something just slightly wrong with his seemingly flawless conquest. His disquiet was growing, and with it, Mycroft's enjoyment. In the end, it was him who ended the evening, saying that he needed to get some sleep to work on a case tomorrow, which was the second blatant lie of that evening.

As they stood on the pavement in front of the restaurant, saying their goodbyes, Mae smiled charmingly and said: "Thank you for your stimulating company, it has been most instructive."

Mycroft gave up then and smirked a little. Pop culture knowledge was not his forte, but he had accompanied his mother to this particular film some years ago and this line had struck him at the time as a rather witty hidden insult. Now, used against his brother, he liked it even more. Sherlock of course was at sea, and so he simply disappeared quickly, leaving them in peace.

Back in Mae's house, as they drank their digestive, she looked at him, a little bewildered, and said: "He doesn't have a clue, does he?"

"About the best way the irritate me? He certainly does."

"Oh yes, he's been practicing it his whole life, I imagine. No, you know what I mean."

"Yes, I do. And no, he doesn't."

"It's so strange. I mean, I knew your dynamics were different from mine and my sister's, that here the protectiveness was apparently exclusively on your side, but I never imagined he wouldn't know. The great Sherlock Holmes, of all people, and he doesn't have a clue! How can he not know?"

"Frankly, I have no idea. I mean, I'll be first to admit I'm not exactly warm and fuzzy around him, but..."

"But it shouldn't be necessary, you're brothers. I imagine your parents aren't exactly touchy-feely either, you had to get it from somewhere, and yet I'm assuming he doesn't think they don't care?"

Mycroft just looked neutral.

"Oh come on Mycroft," she said exasperated, "I already know your biggest weakness. Knowing that you have caring parents will not change anything when I could use Sherlock against you any time I wanted. He's not that hard to get at."

He sighed. As unpleasant as it was, it was true.

"Yes, Sherlock knows our parents care for him very well, and he cares for them in turn."

"Then this is just weird. Have you ever done anything to make him think you didn't?"

"Not to my knowledge."

"When has this stupid assumption of his started, then?"

"Really, it's been there as long as I remember, or rather as long as Sherlock has been old enough to really think for himself – since he was seven, or something like that."

"Ever since he grew out of that blind child's admiration, in other words." She shook her head. "Well, this is a mystery. Now I know I won't rest till I figure it out."

"Good luck. I've been trying for twenty years, with no success."

"Having a bit of distance usually helps in these matters, you know."

Mycroft stopped by at 221B the next day to chew his bother out for that dinner. He found him in a sulky mood, and Irene Adler in an inordinately good one.

"I've heard you had an enjoyable evening yesterday," she almost purred.

By his brother's irritated growl, Mycroft deduced she wasn't referring to Sherlock's seeming success.

He raised one eyebrow: "What did Sherlock tell you?"

"Oh, he asked me to interpret. Said he wasn't quite sure what had been going on there, and if I could perhaps figure it out."

Mycroft started to smile, too. "I take it you were able to do just that."

"Indeed. I might tell you that Sherlock wasn't best pleased, but I, on the other hand, was greatly amused."

"I'm glad I could be of assistance, then."

"Have you two teamed up against me now?" Sherlock asked sulkily.

"It's no less than you deserve, dear," Miss Adler replied, "for flirting with your brother's girlfriend all evening."

"You know it's not really his girlfriend."

"Still. It's bad form."

"Oh please, since when do you care about form?"

Miss Adler only smiled. "You have to know the rules to be able to break them properly."

Sherlock, in his turn, forwned. "Well, that's what I did yesterday, yet you don't seem satisfied."

"No. There was too much...how to say it...too much sentiment in your attempts. It lacked certain lightness. Your style needs practice."

"Oh please, no," Mycroft muttered, and Irene Adler laughed.

"I don't mean on you, obviously," she said, "I don't think Sherlock will ever want to see your girlfriend again, honestly."

"I did warn him."

"Yes. But you were exactly right – he does think he's the only person with a brain in the world sometimes. So I say it serves him right."

"Fine," said Sherlock suddenly, explosively, "if you two understand each other so well, I can just leave you to it."

Irene Adler laughed again, a loud, thinking laugh. "Jealousy doesn't suit you, Mr. Holmes," she said.

"Jealousy?" He scoffed. "Please. You don't seriously think I would be jealous of him of all people?"

"Well, I don't know," Irene smiled wolfishly and stalked towards Mycroft, just as scantily dressed as usual. "Perhaps?"

Her eyes were inviting Mycroft to play along, but he didn't particularly want to get involved in their disputes, and besides, contrary to Sherlock, he didn't actually want to hurt his brother.

"I assure you that if you did, it would have been completely misplaced. While I have great respect for Miss Adler professionally..."

The woman rolled her eyes at him. "Spoilsport," she said.

"Don't take it personally Irene, you just don't have enough secret information any more for him to be interested."

"Actually, it's more the lack of patriotism that disturbs me," Mycroft said, quite truthfully. If it wasn't for that, and for his brother's infatuation naturally, he wouldn't have objected to encountering Miss Adler from time to time in his semi-secret flat. Though he still thought that she was a better character match for his brother than for him.

"And the fact that he means it is all you need to know about him, really," Sherlock noted disdainfully.

"It is probably the strangest reason I've ever been rejected for," she agreed. "Though there weren't really that many in the first place. But then, that's just what makes your brother interesting, you know."

"Oh, here we go again."

"For someone so absurdly arrogant most of the time, he can be rather uncertain of himself, don't you think?" She asked Mycroft.

"I believe he never quite got over that line of yours...how was it? ...ah, I know. 'Not you Junior, you're done.'"

"He knows that was part of the game, but..." Miss Adler considered, "you know that you might be actually right?"

Of course he was. "If you want a peaceful evening, I suggest you tell him exactly why you prefer him to me. Though I'm sure you understand that I'd rather not be present when you do that."

"I don't think you'd be offended, it's all the character traits I believe you're glad not to have. But you are right that there is a bigger chance the evening will develop into something more interesting if you are not here...unless...I don't suppose he would agree for you to join us in a menage a trois?"

"I do not think so, but in any case, the question is entirely academical, since I would never agree to such a thing in the first place."

She curled her lip, though her eyes smiled. "Prude," she said, and then to his brother: "See? This is one of the reasons why I might actually prefer you to him, even though you have less secret information."

"Because you think I'd agree to a threesome with my brother?"

"Because I think you'd agree to a threesome at all. Perhaps we could try asking John?"

Mycroft judged it was high time he left. He had wanted to ask about their progress in the Moriarty case – he didn't actually know if his brother decided to trust her already – but that could be done another time.

AN: Mae's parting line to Sherlock is from Pride and Prejudice (the 2005 film), uttered by Elisabeth Bennet to Caroline Bingley, and I love it.

Also, my head is now full of threesomes. Oh well.