Like what my grandpa used to say, "if you're with a minor, you usually take them at the back of the diner.
Do you think your Grandpa's joke is appropriate?
It's nothing, I love my grandpa. He was a great man who did many good deeds.
I was not trying to say your Grandpa was a bad person. However, that joke he told trivializes the experience that victims of child abuse go through. They suffer greatly and jokes like that make them feel small and like their experience meant nothing.