The books have very little overt sex in them.
The discussion of sex in the books is not a bit out of line with what is normal in literary works, particularly of the realist sort. Sex is implied, or baldly discussed, but rarely if ever shown, and then without prurience. It is a very adult sort of treatment of life.
Consider Flaubert, Balzac, Zola or Hugo.
As for what HBO did, that is their doing and not essential to the work. The series would be substantially better with some editing of HBOs extra features.
Watched the first season, and several minutes actually went by between copulations. Found a lot that was pretty, the stunningly beautiful dogs, the theme music. That reminds me…most of the sex was doggy style. Never watched the second season.