Given that we have already had two rape jokes in this thread, you might want to reconsider your notions of what people "can" and "cannot" do here.

Additionally, I need not "tease out a scenario" where it "might be okay" to make a rape joke. I am knee deep in such scenarios (unless you actually believe jokes about rape to be morally wrong, rather than merely distasteful; I know I don't). Less common are scenarios where I can make a rape joke without negative social consequences, but there's still no shortage of those, either.