若要人不知，除非己莫为的英文

此外，If you don't want people to know, you'd better not do it, If you want to keep sth. from people, don't do it, The only way to prevent people from knowing is not to do it, 等词也有 “若要人不知，除非己莫为”之意，具体用哪个要根据语境来定。