“Join me and together we can leave this mortal coil and be bathed in the eternal essence of absolute evil!”
“Sure,” said the hero.
“What?” said the villain. “Aren’t you supposed to say something like, ‘I will never join you! You and your dark ways are blah, blah, blech, etcetera, etc, and you know the rest?’”
“I thought about it. But you give a pretty convincing argument. I’ll join you. Sure. I’m convinced. Let’s go be evil and stuff!” (Couch Face: the Closet-Case Heterosexual).