A few more years and we'd slip further, into the bright, white bald-headed life of THX-1138 (1970), George Lucas' art-house sci-fi first feature, expanded from a student film he did at USC. Robert Duvall stars with Donald Pleasance (an easy bit of casting); look for cameos by Yul Brynner and Chiang Kai-Shek. Imagine a world of naked sadism, prescription drugs and robot policemen where the only erotic words are "no one is watching," and everyone really is. Imagine a bleak, bleached future in which "sexual perversion" (in this case, just regular sex) was a punishable crime!
Oh.
Alas, our beloved yesss-man, we hardly knew ye. Except at the end, of course, when we found out a whole lot more than we ever wanted. Was it Love at First Bite (1979)? Or perhaps just 1975's Jaws.