you must be kidding (冗談でしょう): You won the lottery? You must be kidding! (宝くじに当たったの？冗談でしょう！) - 試験に出る! 英単語検索辞書

you must be kidding (冗談でしょう): You won the lottery? You must be kidding! (宝くじに当たったの？冗談でしょう！)

You won the lottery? You must be kidding!