I'm a librarian who loves anime, manga, and reading a wide variety of genres.
Gurgeh has been invited to someone's estate (in an Empire outside the Culture). He has just been told that one of the ladies is interested in him and that it's totally cool if he has sex with her:
"I'm most grateful. I shall certainly try to relax; but I was told before I came here that I would be found ugly, even disfigured, by your people. Your kindness overwhelms me, but I would prefer not to inflict myself on somebody who might not be available through choice alone."
Either he's being cautious and pretending to be polite and humble, or he has completely forgotten the prostitutes he almost had sex with earlier in the book.
He has also taken to watching torture porn. Flere-Imsaho assured readers that he doesn't get any sexual pleasure out of it, so I'm guessing he watches it to stay angry and thereby better his game. Or something? Either way, it's time for a fluffy manga break.