Sleaze.
Before there was widespread porn or even the technology to play it at home there was sleaze and it was playing constantly at drive-in's all across the country. You know that scene in so many films where a young guy and gal are at the local drive-in and it's clearly about to go down? What those scenes so often get wrong is that the movie on the screen would be some flavor of strange hyper-niche softcore with a level of nudity never seen before.
Drive-in's, like pinball, was some serious scumbag shit. Imagine!