Rape is a terrible crime.
So are murder and torture, but lots of people here (myself included) joke about that.
...That being said, it depends on the joke, and knowing rape jokes, very few (read: almost none, to the point where I don't remember ever reading a good one) are actually in any way remotely good or funny. And regardless, this guy needs his ass kicked to Pluto and back.
The far side of Pluto.