Mistletoe
John was on a mission. This was his and Sherlock's first Christmas together and he was sure to make it better than the last. Decidedly an easy task, being that last year was nothing to smile about. It was the perfect moment to strike; Sherlock was on a post-case high and would consent to anything. Mostly.
"John what on Earth are you doing?" Sherlock says, as he watches John hang multicoloured lights on the mantel. John doesn't respond, obviously trying to delay the inevitable admittance of his actions. Sherlock huffs at being ignored and sits down in his chair with obvious irritation. After placing a Santa hat on top of the skull, John steps back and admires his work. He turns to look at Sherlock for some small sign of approval but is met with a half-hearted glare.
"Oh, come off it. It's nearly Christmas!" John said, walking into the kitchen to retrieve more decorations from the box.
"Please John, it's hardly dull. All the hype for a week of torturous shopping, uncomfortable family visits, even more unsettling dinners, and then the giving and receiving of gifts that more than likely will end up broken, lost, or resold within two months." Sherlock says, his irritation becoming more evident.
"Just," John sighs, "just let's try to enjoy it?" Sherlock turns to return a scathing remark, but is puzzled by what John's doing. He saw the doctor standing on the tips of his feet, reaching towards the doorway of the kitchen, but struggling.
"What—"Sherlock starts, but is interrupted by John's cry of triumph as the sprig of greenery just barely sticks to the top of the doorway.
"Don't tell me you don't know what mistletoe is." John says, quirking an eyebrow at Sherlock. He watches as the consulting detective saunters over and inspects the plant.
"Mistletoe, Phoradendron Flavescens, a hemiparasite. When mixed to drink, it can improve blood circulation and also helps internal bleeding." Sherlock recites from memory. John laughs and Sherlock frowns.
"Was I wrong?" Sherlock asks
"Ah, no I don't think so." John says, smothering a grin.
"Then what?" Sherlock says, trying to remember more about the plant.
While Sherlock is thoroughly distracted in his Mind Palace, John grabs him by the shoulders and brings him down for a kiss. Sherlock is surprised, but finally relaxes and pulls John closer. Before it can transcend into anything more intimate, John pulls back.
"Do you remember now?" John asks with a small smile.
"It's coming back to me." Sherlock smiles and pulls John back in.