Heterosexualis (1973)

Starts with this hot blonde MILF in a scarf holding a knife near a door — not scary, just a tease. Then she’s at a dinner table with a suit guy, talking and getting handsy. Next scene she’s naked on a bed, straddling him while he’s still in his suit pants. She leans down for a messy blowjob, lips tight around his cock, then climbs up and starts riding him slow at first, then faster. Camera gets right in there for a good look at her tits bouncing. Later the suit guy’s alone in a white shirt, jerking off while adjusting his hard-on through his underwear — no full nudity but you see the outline. Last shot she’s covering up with a towel while he positions her, probably for doggy or something else. Good lighting, decent angles, nothing too fancy but the riding scene is solid.