Sweet Bird of Aquarius (1970)

The scene opens with a slim, long-haired blonde in her 20s already on the bed, wearing tiny panties, lit by a dim lamp. A muscular brown-haired guy in his 30s walks in from the hallway, kicks the door shut and goes straight into a deep kiss. They embrace tight, clothes come off fast — he’s got a thick cock and she teases it with her fingers before taking it in her mouth. She rides him in reverse cowgirl, bouncing hard, looking back at him the whole time. Later, they switch to missionary with plenty of face shots — she gags a little when he pulls her hair during deep throat. The lighting stays moody throughout, lots of skin on display and zero wasted time on lame dialogue.