I know, "it's just a joke" but the fact that you care so little that you accept the idea of rape being funny, just goes to show inconsiderate you are. Rape is not some obscure thing that hardly happens to anyone and is ok to joke about because, hey, it's not like a rape victim would see this.
The scary thing is-- and it's true-- many rape victims are actually told "no one can hear you." Do you understand how triggering this could be for someone who actually survived rape?
Rape is real, rape is prevalent; rape is not something to joke about. Ever.