"Spring in Fialta" by Vladimir NabokovRead about another entry on the list.
Here’s my theory: just as the most effective horror movies leave the horror unvisualised (The Blair Witch Project, Paranormal Activity etc), the best sex scenes are ones that leave the sex undescribed, so you can do the imaginative work.
One morning, Nabokov’s narrator meets again the diverting woman in the grey suit in a Parisian hotel corridor. Every word is – if you’re in the mood for a bit of the other – sexual. She’s “waiting for the elevator to take her down, a key dangling from her fingers.” Her husband, she confides, has gone fencing. She leads him back to her room where “because of our sudden draft a wave of muslin embroidered with white dahlias got sucked in, with a shudder and a knock, between the responsive halves of the French window, and only when the door had been locked did they let go of that curtain with something like a blissful sigh; and a little later I stepped out on the diminutive cast-iron balcony beyond to inhale a combined smell of dry maple leaves and gasoline …”