I thought with a sensation of madness on my promise of creating another like him, and trembling with passion, tore to pieces the thing on which I was engaged. The wretch saw me destroy the creature on whose future existence he depended for happiness, and with a howl of devilish despair and revenge, withdrew.
– Mary Shelley
Frankenstein, Chapter 20. Victor decides not to create a mate for his creature, after thinking about some of the dire consequences, like the possible mating of the two creatures. This provokes the creature to seek vengeance on his creator.