John walked up the stairs of 221B Baker Street, the sight of Sherlock sitting in his chair still a shock to his system. It was only a week ago when John had returned from another mundane shift at the practice to find Sherlock sitting in the exact same position he was now. 3 years ago John wouldn't have blinked to see Sherlock sitting in his arm chair, but that was before everything with Moriarty. And before Sherlock jumped off the roof of St. Bart's.
John remembered that cold January day as if it was yesterday. His frequent nightmares still haunted him; seeing Sherlock on that roof, hearing the agony in his voice as he said goodbye, and feeling absolutely nothing when he felt his wrist. Sherlock's suicide destroyed John. He'd had friends who had died in horrific ways in Afghanistan, but none had ever caused him this much pain. Because none had ever come back.
"Spag bol for dinner. Is, er, that ok? Sherlock?" Saying his name so casually felt so strange. But equally wonderful. John placed the Tesco bags on the kitchen table and started to take out ingredients ready to prepare spaghetti bolognese.
"Who else is coming?" Sherlock perked up, his eyes scrutinising John's.
"Sorry?"
"Who is the third person joining us tonight?" John's face remained baffled, wondering how Sherlock knew he'd invited a guest. "The ingredients. There's enough there for at least 3 people. You've never bought extra when it's just us."
"Oh, erm, yeah." John would have to get used to not being able to have any secrets again. "Molly. Molly is coming. Hope that's alright." John twitched an innocent smile at Sherlock.
"That's fine," Sherlock replied, in a deep monotone.
John was laying the table when the doorbell rang. Sherlock hadn't moved from his seat all evening, leaving all the cooking to John. As soon as the bell rang John trotted down the stairs to greet Molly. Sherlock's head snapped towards the door; John never usually greeted people downstairs. Something was up.
"H-hi. Hi, Sherlock," Molly squeaked as she entered the flat. John took her coat and Molly awkwardly approached Sherlock, her eyes not flickering away from his face. This was the first time she had seen him since he had returned. Sherlock stood up and went to greet Molly, but before he could say anything she flung her arms around him, before quickly recoiling. "I'm sorry. I...I've just missed you." Sherlock straightened his shirt and flashed her a killer smile.
"That's alright, Molly. Shall we eat?"
"Sherlock," John said seriously, not moving. Sherlock turned around to see John and Molly both looking rather nervous.
"What? What's going on?" Sherlock hated not being in the know. However, his confusion was cleared up when he saw John's hand intertwine with Molly's. "Oh."
"Sherlock, look," John started, a hint of guilt in his voice. "Molly and I got close after...after you left and..."
"John. You don't need to explain. I'm very happy for you both." He gave a courteous nod and turned around and took a seat at the table, Molly and John following.
Dinner went by quietly. John tried, in vain, to start a conversation several times. Sherlock didn't look up from his dish until he'd finished his meal, at which point he got up and resumed his position in his chair. John and Molly talked in low voices as they cleared up the kitchen, Molly letting out a high-pitched and girly giggle a couple of times. At about 9pm, an hour after dinner, they headed for the door. Molly mumbled a shy goodbye to Sherlock, who mumbled one back. John fetched her coat and hung it around her shoulders before putting a stray strand of her hair behind her ear. He said something to her quietly, making Molly giggle again, Sherlock now watching with intrigue. John said goodbye before planting a gentle kiss on Molly's pink lips.
Sherlock saw this small, sweet act of intimacy and felt something in the pit of his stomach. Sherlock snapped his head back, focusing on a point directly ahead of him as he realised what that feeling was. Jealousy.