From The Godfather
Author: Mario Puzo
Participants: Sonny Corleone, Lucy Mancini
Worst Line(s): "Her hand closed around an enormous, blood-gorged pole of muscle. It pulsated in her hand like an animal and almost weeping with grateful ecstasy she pointed it into her own wet, turgid flesh. The thrust of its entering, the unbelievable pleasure made her gasp, brought her legs up almost around his neck, and then like a quiver, her body received the savage arrows of his lighting-like thrusts."
This scene is mostly hilarious for the fact that Mario Puzo wrote in a character (Lucy) with a wide-set vagina for Sonny Corleone's elephant dick, and then proceeded to make it a crucial plot development.