"Do you know how badly I want you right now?" John's voice growled as his fingers applied just the right amount of pressure.
Sherlock gasped as he felt his cheeks flush. He hadn't expected this from John, nor his body's oh-so-obvious reaction to the sound of John's voice and hand on his throat. It had just been an experiment, to see what would happen to a body when all sensory areas were stimulated. And Mr. "I'm-Not-Gay" John Watson's reaction was not what he had predicted.
John, on the other hand, was fed up with being a guinea pig. He'd finally accepted his body and heart's reaction to his flatmate, but had been hiding it to maintain the peace. But this, this, was too much. Sherlock being so close, smelling of leather, expensive cologne, and something that was just "Sherlock", his tight shirt, that baritone voice in his ear as Sherlock's lips brushed his sensitive lobe. And the wanker had made him tea! The last two told John all he needed to know, that he was Sherlock's current "experiment". So John decided to do a little "experiment" of his own.
In one swift move John (he had been a solider after all) spun around and had Sherlock pressed against the wall, one hand grasping his throat and the other on his arm. He didn't care that the tea had soaked the carpet and was dripping down the wall. He wanted to see and feel Sherlock's reaction. It was all he'd hoped for. Sherlock's pulse quickened under John's fingers, a small moan escaped his mouth, and John felt Sherlock's erection against his thigh. Turning his head, John captured Sherlock's mouth with his.
Sherlock's experiment quickly went from observing John's reactions to sensory stimuli to his own sensory overload. Sherlock was drowning in John. The taste of his mouth (tea, biscuits, tangy), the smell of his skin (crisp, outdoors, sandalwood), skin on skin (stubble on his chin, calloused strong fingers), low rumble in his voice (that stirred a fire in Sherlock's belly), the intensity in John's eyes (this is real he wants ME), all these things made Sherlock light-headed and off kilter. If John hadn't been holding him up he might very well have hit the floor with his realization. He WANTED John Watson like he'd never wanted anything before in his life.