In The New York Times' April 14, 1967 movie review, by Bowsley Crowther, the era's less prurient mores led to this screed:
"A raw and unmitigated campaign of sheer press-agentry has been trying to put across the notion that Warner Brothers' Bonnie and Clyde is a faithful representation of the desperado careers of Clyde Barrow and Bonnie Parker, a notorious team of bank robbers and killers who roamed Texas and Oklahoma in the post-Depression years.
"It is nothing of the sort. It is a cheap piece of bald-faced slapstick comedy that treats the hideous depredations of that sleazy, moronic pair as though they were as full of fun and frolic as the jazz-age cutups in Thoroughly Modern Millie. And it puts forth Warren Beatty and Faye Dunaway in the leading roles, and Michael J. Pollard as their sidekick, a simpering, nose-picking rube, as though they were striving mightily to be the Beverly Hillbillies of next year."
On further reflection, and after a little digging on Wikpedia which confirmed that the Motion Picture Association of America's ratings system wasn't introduced until a year later in 1968, I remembered that my first R movie was actually MASH in 1970, which I saw in NYC with a classmate who's father was divorced and lived in Manhattan. After the movie his father saw us off at Grand Central, stopping first at a newsstand to get us a magazine to read on the train home, that month's Playboy. A lot had changed in three years.