John's hair was all rumpled; he must have only just pulled his jumper on. "Running a bit late, are we?" Sherlock asked with a grin, catching his partner by the waist and kissing him.
"Yes, we are. I would've been ready ages ago if someone hadn't taken so bloody long in the shower," John pretended to grouse, pulling free of Sherlock's hands and stepping into his shoes.
"I was hoping you'd join me," Sherlock replied smoothly, pulling their coats out from the closet and helping John into his. They hurried outside to the cab Sherlock had waiting, and pulled up to the Yard only a few minutes later. The building was lit up with Christmas lights and Sherlock could hear the tinny music from where he stood on the sidewalk. For a moment he was overcome with anxiety. He'd never attended one of the Yard's parties, or any sort of party other than ones he'd thrown himself or been forced into by Mycroft. John, sensing his partner's nerves, took Sherlock's hand and gave it a reassuring squeeze before walking inside.
Immediately Molly came up and hugged them both, even giving John a kiss on the cheek, leaving a small smear of lip gloss that Sherlock whisked away a moment later with his thumb. Greg came over and clapped a hand on Sherlock's shoulder, smiling gruffly in a way that said, very clearly yes I'm involved with your brother and no nobody here knows. Sherlock and John both nodded their understanding and made their way over to the punch bowl.
Sherlock poured them both a cup of punch and took a sip while he watched the party. John wrapped an arm around Sherlock's waist. "Don't look so anxious, this isn't a test. It's a party, enjoy yourself," he whispered quietly. Sherlock nodded curtly, unable to really respond due to nerves. It didn't make sense, this sudden anxiety over a party of all things. He'd faced down serial killers and gunmen, but place him in a room full of people he considered friends and he shut down.
John recognized it immediately, and found a remedy. "Here, just take my hand and follow me. If in an hour you still want to go, we'll leave, deal?" Sherlock agreed quickly, knowing how much John had looked forward to the party and silently swearing to make it through.
They went about, making the rounds and chatting with the Yarders over this and that. John had the strangest memory for personal details. He remembered to ask Donovan how she liked her new flat, Greg how the new car was running, and even asked Anderson how things were going with the new girlfriend. Sherlock could see the answers as plain as day in their faces and clothing, but somehow John made asking seem like the better option to observing. Sherlock noted it for use later.
Soon an hour had passed. John gave Sherlock a questioning look as if to ask do you want to go? Sherlock shook his head. He was enjoying himself thoroughly. Seeing John like this, moving easily through waters that had terrified Sherlock only earlier that evening… it was brilliant. When the party finally died down and they were on their way out, Sally smiled and them both.
"Thanks for coming… Sherlock."