Operation Orient (1978)

A slim brunette with long dark hair is doing most of the work here, riding a guy in a dimly lit living room. The camera catches every bounce as she leans back, hands on his thighs, her smallish but perky tits jiggling with each movement. Later she flips to doggy, bent over the same chair, ass in the air, taking it deep while he pulls her hair. The lighting’s low but clean — you see sweat on her back, the guy’s determined thrusting, and plenty of facial expressions. No extra scenes or distractions, just straightforward bedroom and living room fucking. The guy isn’t super big but he’s into it, and she’s moaning loud enough to make it feel real.