He lets out a small moan at her instruction. It's exactly what he wants, he wants her to tell him and---

Somewhere in his mind, he's aware that he should move more slowly with this. That his affection for Watson is about more than sex, and he shouldn't focus on it. But then again, the way she's whispering her instructions? How is he supposed to resist?

He presses his lips to her nipple, and then traces his tongue slowly. Not teasing, so much, but taking his time. Relishing in her every reaction. He moves in to graze his teeth, then to suckle.