it's very simple, they blur/remove the line of demarcation between what is an adult and what is a child. It all starts with language, and behavior, they speak like kids and act like kids which then has the kid thinking they are an adult b/c "they are being treated like one", not understanding that the situation is 180 degrees opposite, the groomer has taken on the guise of child which leads to manipulation. The rest of what happens is rather obvious from that point.