Sherlock hated it when John whistled.

Which was precisely why John did it. For the most part.

But there were times when he did it because he was happy too. Today was one of those times. Everyone knew why John was happy and Sherlock had been warned that he wasn't to destroy that. Not today of all days. He had even been threatened, for goodness sakes. Lestrade had said he wouldn't call him in on any interesting cases for a month if Sherlock got stroppy with John. And he'd had that look in his eye that said he was serious too.

He was still trying to decide how he was going to get Lestrade back for that.

He heard John come down the stairs from his bedroom, and turned around from his computer to watch him attempt to do up his tie. He watched, amused, for a couple of minutes and then, rolling his eyes, he got up to do it for him.

John grinned up at him. "Thanks."

"I would think that a grown man, an ex-soldier no less, would have figured out by now how to do up his own ties."

"My mum always did it for me. And I haven't had much cause to wear them for years now." The smaller man shrugged, still grinning, and straightened his shirt. Sherlock eyed the cufflinks made of white and yellow gold. New. A gift. Interesting. Must be from Lestrade. "Why don't we just say I deleted the knowledge?"

Sherlock rolled his eyes at him and went back to his computer. John chuckled and picked up his jacket from where it was lying over the back of the couch. "Don't wait up tonight. I think we're going to go back to Greg's place."

Sherlock grunted and filed the information away in the temporary folder in his head marked 'John's Plans for the Evening'. He'd be happy to delete that folder later so he could fill up that space with the results from that experiment with the mould…

His mouldy thoughts were interrupted by the slamming of the door downstairs and the muffled, 'Good evening, Mrs Hudson. Yes, hard to believe, isn't it? An entire year already.' There were steps on the staircase, two at a time if Sherlock was any judge (and he was), but the sound was different from his regular shoes, but he wasn't wearing trainers. New dress shoes, then. He eyed John in his new suit. Hmm. Special evening.

The door opened and Lestrade stopped dead in his tracks as he saw John. He eyed him up and down and then smiled in an almost…feral way, Sherlock would have said. "You look wonderful, John."

John smiled appreciatively. "I could say the same."

They smiled and undressed each other with their eyes until Sherlock cleared his throat and they both jumped guiltily. He stood and approached Lestrade. The man had something under his arm that looked remarkably like a folder.

He held his hand out. "You have something for me?"

Lestrade dragged his eyes back to Sherlock from where they had strayed again to John. "Um. Yes." He held up the file. "A peace offering, since it looks like you actually listened."

John's ears pricked up. "Listened?"

"Sherlock was under strict instructions not to upset you today. I wasn't going to have anything ruin our night." He held out the file to the detective. "A cold case from twenty years ago to keep you occupied."

Sherlock started to reach out with one hand, while listening to the little voice in his skull that was telling him that this was his chance to get Lestrade back. The man's attention had drifted back to John and he wasn't paying attention. Sherlock's left hand darted out and slipped unobtrusively into Lestrade's suit pocket. A box. Hmm.

He pulled both hands back, hiding the movement of his left with the file in his right. Not that Lestrade would have noticed anyway. Sherlock smiled cheerily at the two men. "Have a good night."

Sherlock was quite proud of his restraint. He waited until the taxi carrying the two men had pulled away from the kerb.

The box was small, square in shape and it had the imprint of a well-known jeweller on the lid. He opened it to find a ring within. A man's ring, a plain band of yellow gold in the middle with two thinner rings of white gold on either side. Nothing ostentatious; a simple ring, but obviously well-made. But what on earth was Lestrade doing with such a ring?

Wait.

Sherlock froze.

What was that Lestrade had said as he came in the front door? He accessed his delete pile – he hadn't bothered to get rid of the extraneous information of the past little while yet – and recalled what Lestrade had said to Mrs Hudson.

Yes, hard to believe, isn't it? An entire year already.

Uh oh.

This could be, might possibly be, one of those things that John would label as 'A Bit Not Good'.

He sifted quickly through the information he kept in his head about rings.

Ring, meaning of dirt on the outside…no, that's not it.

Ring, meaning of being clean on the inside…no, not that either.

Ring, meaning of big diamond versus small diamond…no.

Ring , meaning of when given in conjunction with a question being asked…

Yes, that was it.

And oh yes, this was definitely A Bit Not Good.

They were both going to kill him.

Sherlock's mind whirled. Where on earth had they said they were going tonight?

He gave up after only a couple of seconds. John had told him the name a couple of days ago, but he'd already deleted that information since he hadn't considered it important. He was perhaps going to have to rethink that policy in some way. All things pertaining to John and Lestrade's outings might have to be kept for emergencies like this.

His phone! Yes, a quick text to John and he'd find out where they were.

He tapped the message in. Must know to which restaurant you and Lestrade have gone.

His phone beeped a couple of seconds later.

If you think I'm telling you so you can come and crash our anniversary, you truly are insane. And I'm turning my phone off now.

He didn't bother texting Lestrade as he would have already turned his phone off at John's prompting. Sherlock growled and threw the phone at the couch. It would have been the wall but John would get mad at him if he broke another one this month. Well, it wouldn't be hard to figure it out.

He steepled his fingers and thought hard.

Both of them were wearing new suits. With freshly shined shoes.

John had those new cufflinks. He winced. He realised now that they matched the ring. Lestrade wasn't going to give him any new cases for a year if he didn't get the ring back to him before he went looking for it.

Anniversary. Dinner then. Somewhere expensive.

Think, think, think…

And then it came to him. Lestrade had asked him at that crime scene the other week whether or not John liked French food. Said a new French restaurant had just opened up. And Sherlock hadn't deleted that because he was going to use it to needle Mycroft who loved French food. Wonderful new French restaurant, Mycroft. Too bad you're on a diet…

Sherlock snorted. He still planned to use that. But for now he just had to find it. A couple of minutes online and he was out the door.

At Chez Michel, John wiped his eyes and tried to get his laughing under control. He was getting irritated looks from the other diners. Lestrade still looked thunderous, but even he was starting to see the humour of the situation.

"Well, you have to admit this is pretty typical for the three of us." John started to giggle again. "How long do you think it'll take him before he realises what he did?"

"Not long. But he's in trouble."

"Of course he is, Greg," John agreed, "you'll be able to use this to make him do what you want for ages."

"How long until he gets here?"

John looked at his watch and considered. "Well, I'd say…three, two, one…"

Simultaneously, their head swiveled to look out the window. A cab pulled to a stop and the man in question swirled out of the car, one hand closed into a tight fist.

Sherlock looked around and spotted the door to the restaurant. As they watched he suddenly shoved his fist into his coat pocket and strode for the door.

He was met by the maitre d' as soon as he entered. "Ah, monsieur, we don't 'ave a table at ze moment…"

"I don't want one. I'm just here to see two of your customers." He looked at the maitre d'. "And drop the phony accent. You're from the East End."

Sherlock ignored the shocked scowl on the man's face as he made his way to John and Lestrade's table. "Ah, Lestrade…" He stopped and for once, looked unsure of himself. "I must speak to you. About that cold case. It will only take a second."

John and Lestrade would agree later that Sherlock would have realised they already knew about the ring if he had been paying better attention. And they agreed that it was a sign of how badly he felt that he was so preoccupied that he didn't notice. And they would further agree that they were simply thrilled that he was so preoccupied so they could have some fun.

"Oh, Sherlock, not now. It's a twenty-year-old cold case. It can wait another day." Lestrade made sure to smile lovingly at John.

A faint aura of panic started to waft around the detective. "Ah, no. No, it can't. I must speak to you now."

"Sherlock," John's voice was firm as he stretched his hand across the table to take Lestrade's. His left hand. He noted with barely contained amusement how Sherlock followed the movement and swallowed. Hard. "It's our anniversary tonight. You must know how very special that is."

"Yes, yes, of course I know. But I assure you, Lestrade, I only need you for a moment and I will leave you both alone for the rest of the evening."

"Actually, Sherlock, I'm glad you came." John saw Lestrade's mouth quirk up in a grin, and suddenly he knew what he was going to do and it took all the willpower he had amassed in the army not to laugh. He saw Sherlock pale as Lestrade started to shift out of his seat. "It seems only fitting that you witness this."

And with that Lestrade slid to one knee in front of John, while behind him Sherlock's eyes widened. The DI started to reach into his pocket when Sherlock finally gave in. "Lestrade, don't…"

Greg cocked an eyebrow at him. "Don't what, Sherlock? Is there some reason I shouldn't propose to the man I love?"

Sherlock's eyes narrowed and John couldn't help himself. He started to laugh again. And watched as the detective started to blush. Irritation and embarrassment warred for dominance on the man's face. "You already knew I had the ring."

"We did," John allowed.

"And you thought it would be amusing to make me admit it."

"Definitely." Lestrade held out his hand. "The ring, Sherlock."

The detective reached into his pocket, pulled out the box and slapped it into Lestrade's palm. He looked, John thought, like some demented version of a ring bearer at a wedding. A six-foot tall, rail-thin, scowling nutter of a ring bearer.

Now that, John thought as his eyes lit up with unholy glee, would be sufficient payback.