Watson gave a bit of a jump. He glanced over his shoulder, laughing, and bent to pick up the collar that had he had dropped in his surprise. He couldn't quite name what had possessed him to indulge in something so outlandish as a little playful spanking, but he was glad he had, and he was glad it had been received so well.

"Do you really think that's necessary?" Watson said, smirking. "Is such punishment really deserved? How cruel you are."

He continued to be surprised at just how far he was willing to push himself with Holmes, what boundaries he was willing to explore. With most women, he wouldn't have dared, and it would have gone badly if he had.