you have (got) to be kidding idiom
informal (also you must be kidding)（表示对某人的话非常惊讶而且不相信是真的）别开玩笑了
used to show that you are very surprised by what someone has said and do not accept it
You want me to drive into the city? You’ve got to be kidding. 你想让我开车去城里？别开玩笑了。