He isn't quite sure he'd define skinnydipping as unspeakable and immoral... Perhaps immoral, but not unspeakable. That, however, is thankfully not what Watson is asking, and so Holmes can safely mislead him. Maybe Watson will be so delighted by that that he'll kiss Holmes again. He doubts it.

"Yes, and yes," he returns, rather unashamedly watching Watson. "I'm afraid you're quite disappointing me. This is your last chance."

He slips his trousers and small clothes off and folds them up, setting them atop his shirt. It is a little odd to be standing naked on a beach, not to mention a bit chilly.

"And please guess quickly," he adds, impatient.