I Love It From Behind! (1981)

Starts with this skinny Asian girl in a black dress just standing in a hallway, looking all innocent. Then she meets up with her two friends—another Asian girl with glasses and a white guy with messy hair. They hit a bar first, all flirty and touching each other, before heading outside to a park where the two girls start making out. The real action kicks in when they get to a living room. The first girl gets blindfolded and tied up with rope while the guy watches, then he fucks her from behind hard while she’s still restrained. The other girl joins in, getting eaten out on the couch while the guy switches between them. Camera gets right in there for close-ups of the doggy style pounding, and you can see how tight both their pussies are. No fake moaning, just real heavy breathing and the sound of skin slapping.