When Mycroft invites the Watsons, Lestrade and the Holmes family (including the newest "member" of the family, Molly Hooper soon-to-be Mrs. Holmes) to his place to celebrate New Year's Eve, Sherlock asks Molly to wear the emerald Green dress he gave her for her last birthday. It's long enough to cover her new heels and the lack of underwear he asked for as well; low cut on her back, revealing the soft pale skin of her back, and when she excuses herself to go to the bathroom after dinner, Sherlock can't help but notice the way her hips sway, hypnotizing his eyes.
The animal instinct in him makes him follow her, as a lion chases its prey. She wanders around the corridors and the enormous rooms of her brother-in-law's home, and stops in her tracks as she enters the library.
Books about politics, economy, classic literature and maybe even some medical books are part of his collection; mesmerized, she wanders around the room.
When Sherlock finds her, she's turned with her back to him; he walks to her, already unzipping his fancy suit trousers and walking till he's against her back, grinding his cock against the soft, green silk material. She bites her lip to suppress her moans, already wet with anticipation. She's about to hold onto his cock, when he makes a move and abruptly turns her around, lifting her dress and smirking triumphantly as he stares at her pelvis, exposed, shaved clean and already wanting him. He's already hard, wanting and leaking for her; wasting no time, he pins her against the bookshelf and pushes his hard and wanting member inside her, penetrating hard and deep, but lovingly, just the way they both enjoy it.
Molly comes first, the thrill and excitement to please her man making her muscles clench around him, squeezing deliciously as she moans against Sherlock's ear. This causes him to reach his climax, coming inside her, marking her as his and letting their love and passion mix in one.
"That color suits you," he whispers against her ear, his climax bringing him back to reality.
"Sherlock Holmes, you always know how to flatter a girl!" She smiles and kisses him deeply and passionately.
After they had cleaned up a bit (meaning another quick shag; Sherlock licking Molly and making her come again and Molly sucking and deepthroating Sherlock, arguing she can't let him get his new suit trousers dirty), they go back to the elegant table where friends and family are talking about the weather in London lately.
Molly takes her place besides Mary Watson as Sherlock Holmes sits on her other side, in between his lovely fiancée and his best friend. John turns to him and whispers "Fix your tie, mate." Molly giggles and Sherlock looks at her with promising eyes. She stares directly into his eyes with love, lust, devotion, and the promise of an unspoken deal between them. Later.