In the image above, he's expecting to do it 4 times a week, but she's only offering once for the rest of his life.
I always assumed that Spock was just hitting Vulcan puberty in Amok Time and before that, "doing it" was out of the question for him. I think that was the author's intention. Spock doesn't have a fun nightlife in that interpretation.
Interesting that since our culture has changed so much in 46 years, people are retconning, or at least reading things differently, to let Spock have some fun.
Edit: now that I think of it, 1970s fan fiction was reputed to have a lot of sex in it, so maybe people haven't changed so much as TV has...