AN: I end with Lestrade because, come on, look at the man! And d'aww Sherlock doesn't know his first name and honestly I should not be allowed near the internet because any fatherly-son moments between them make my heart melt into an embarrasing pool of goo.
He'd heard the gossip, naturally. He'd even given in and called Sherlock himself. The brat didn't answer, of course, but he'd swung by the new flat to ask him personally to help with the fourth suicide and cornered him then.
"So you've got a bloke then?"
Sherlock's mouth twisted in distaste. "I've got John," he said as though that explained everything. "We've been together for one year and seven months."
He'd held up his hands in surrender. "Just asking. To each his own and all that rot. You – er – really like him then? That's why you were so tetchy about that case?"
"Obviously," he sneered. Pale hands tugged a scarf around his throat and then bundled themselves away in dark leather gloves. "Well? I'll not go in a car," he snapped irritably. He turned to a worn in chair and carefully arranged the little union jack pillow there. His eyes were faraway again and Gregory Lestrade had to hold back the portion of his personality that still found puppies adorable and was currently cooing over the worried domestic fluttering the world's only Consulting Detective was currently exhibiting.
But Sherlock had agreed to come and take a look at the body. Sure, he'd slammed the door in poor Anderson's face (though Greg can't say for certain he didn't find that hysterical) and he'd poked around at his phone and the body and paced restlessly muttering to himself.
Gregory Lestrade was just relieved when he saw the tell-tale signs of Sherlock about to begin a deduction when the man's phone chimed obnoxiously loud into the room. Sherlock had blinked and peered at the tiny screen and Greg's sure that he's going to have to wait for that deduction.
"One moment, Detective Inspector!" Sherlock snaps, striding out of the room and whipping down the stairs. He hurries after him and pauses to catch his breath at the door to the building, staring at the scene before him.
There's a blonde man with a cane standing by the edge of the tape and he's got a tiny smile on his face as he waves a little at the rapidly approaching Sherlock. "You were shot!" he hears the consultant shout with a note of actual alarm in his deep voice.
The man grins a little and says something – leaning back just a touch to peer up at the other man. Greg carefully makes his way over and he's somehow less startled than the small crowd of Yarders watching the pair and practically ignoring the scene of the crime. Sherlock roots around in the man's pocket and the man – this must be the mysterious John – just smiles fondly at the top of Sherlock's head.
The little velvet box is a symbol they all recognize and Lestrade lets the smile out this time at the wide-eyed look the glimmer of metal within earns. Sherlock shifts and Greg can't see his face but he sees the gloves get tugged off and the ring planted firmly on his left ring finger where he pauses to admire it.
John looks beyond Sherlock and sees the crowd they've gathered. He looks flustered and it only gets worse when the tallest of the pair picks up his hand and kisses it gently several times all over.
"Sherlock!" he yelps suddenly and the cane rattles to the ground when he's abruptly gathered up to the genius's chest and thoroughly snogged right in front of everyone. Greg hears someone wolf-whistle and sees Sherlock slant his mouth with more fervour over the smaller man's. Then there's a moment for breath and Greg can't help but feel his own catch at the look he can see from where he's standing.
John's looking up at Sherlock, still bright red and flustered, but his smile is soft and wide and his eyes are full of gentle affection. Sherlock's got his lips pulled back in an expression he's shammed before but never been able to pull off that Greg knows of. His blue-grey eyes are bright and roving over John's face as though he's a hundred (thousand – million) times better than any crime scene. He sees Sherlock's lips move again – 'I love you' – and then the detective kisses his fiancé again, gently this time, a bare brushing of lips, before whirling back to stride towards Lestrade.
"Let's go John! Four suicides and a note! It's Christmas!"