He very nearly said that they already did touch one another, but that was obviously the wrong answer to give. Humans placed a lot of importance on reciprocation, especially in intimate relationships, and there was a distinct lack of that in what he had with Nyota. It wasn't anything that had bothered him, and he had, illogically, assumed she took no issue wth it simply because she had never stated that it was a problem.
Until now, anyway.
Spock looked away again, briefly, as he considered what to say. "You would find my experiencing such things enjoyable?" His expression was just barely skeptical. "I find the idea difficult to understand, however, if that is what you wish, I will concede."