The fact that I can jokingly say to my coworker "do it and I might kill you" and they laugh yet if I said "do it and I might rape you" I would most likely get fired on the spot means you are wrong. One the main concepts of comedy is turning something dark into something you can laugh at aka dark comedy. Making the dark issue into something you can laugh about and not take seriously is one of human's prime defense mechanisms. Do you know how paranoid and fucking psychotic the human race would be if no one joked around about dark or screwed up things. A nice example is this: about a year ago a man escaped from prison near my town. They traced him to my best friend's development and issued a manhunt saying he was armed and dangerous. Three days later they called it off for whatever reason. My friends and I were in said development one night and where scared to walk home when our friend said "well aparently the guy wasn't dangerous enough to finish the damn manhunt so I wouldn't be too worried". This made us laugh and greatly lessened our fear of the man. We then all walked home with nearly zero worries. This is why dark humor is a great thing. And this is why rape jokes shouldn't be taken any more seriously than knock knock jokes.