Why Don't Jewish Cannibals Like Eating Germans? They give them gas.
Do you really think it's funny to joke around about the Holocaust and the Jews?
I'm not talking about them at all, I am not making light of the holocaust.
While jokes can be fun, your punchline can be seen as highly offensive to to these groups of people who went through so much. Playing it off as a joke tends to normalize all of this negativity, so I suggest trying to joke about more safer things.