When the abundance of metaphors and similes fly so amazingly out of control that the sex scene in question is barely recognizable as sex, transforming instead into some kind of dadaist word-salad masterpiece, the result is The Literary Review's Bad Sex in Fiction Award.
This year's winner, Jonathan Littell's The Kindly Ones, actually manages to equate female genitalia with "a motionless Cyclops whose single eye never blinks." Also, "a Gorgon's head." It makes you wonder if Littell watched a bunch of Ray Harryhausen fantasy movies before writing this scene! Alas, it only gets worse from there.