Onna Jimuin: Shikijo Seikatsu (1982)

Starts with these two skinny Asian chicks in an office — one’s got a chin-length bob, the other long loose hair, both look like they just walked out of a corporate job. They’re talking to this guy in a leather jacket, average build, standing like he’s about to close a deal. Next thing you know, they’re all over each other in a bedroom. The bob girl goes down on the long-haired one first, slow and deep, like she’s savoring it. Then the guy joins in, doggy style on the long-haired girl while she fingers the bob girl. Camera gets right in there, close-ups on the oral, good lighting so you see everything. They switch it up, guy fucks the bob girl while she rides the other girl’s face. No awkward pauses, just non-stop action.