What's the difference between a Rook and a Bishop? A Rook can only go straight, while the Bishop fucks the children.
Are you talking about the Bishop sexually abusing children?
It is a joke about the rapist priests in the church.
Child sexual assault can be extremely damaging to children and affect their whole lives. Making light about it by joking about priests assaulting children can be hurtful, just like you would be hurt if people made a joke about something that caused you pain.