You could hardly write about the condition of mankind without at some point addressing sex. Of course attititudes to sex have changed dramatically over the millenium and we tend to look back on this through different filters depending on the current vogue.
There was a time not so long ago such talk would have been considered forbidden and disgusting but thats more sign of the time than what is actually written in the Bible.

Even religious types admit that sex is in the Bible ,though it sure it doesnt get many sermons based on those parts.