He moans into their kiss--oh god, this is nothing like how he'd do it himself and that's brilliant. Again his hips rock, a shiver of pleasure sweeping up his spine. And somehow the feeling of her thumb dragging over the wet tip of his cock... inspires him, in a way. Sherlock turns his wrist slightly, adjusting so he can fit his thumb against her clit and the tip of his index finger at her entrance.