Nice try. But it was around 1970 that extramarital sex and pornography became mainstream and `acceptable'.
Before then, these behaviors existed and were confined to the gutter, where they belonged.
Porno chic took it to the mainstream. Famous celebrities flaunted going to see "Deep Throat".
It was on exhibit at the "regular" theaters, not just the "art house".
X-rated records, comics, films, and photos existed in the 1930s and before. They were never on public display and kept out of the eyes and ears of kids. Those kids grew up into adults and even grandparents, yet aren't always aware of just what was out there. The sale of some such materials was criminal.
Now you can get extreme entertainment at Best Buy, Borders, and elsewhere. Do they ID? Or if a movie says "unrated", anything goes? Those ratings don't mean a thing to the American Library Association.
There is a culture war going on. Some think that some things are "age appropriate" while others don't like "rules".