You don't have to tell me.这还用你说/

Today I want to explain the sentence“You don't have to tell me” in English. When people say this sentence to you, I think the meaning is  I have already known what you say and what you mean,  I know what I should do,  there is no need your mentioning this to me, you don't have to make an unnecessary move. Mostly you feel a little bit annoyed or  frustrated when people say this.  For example,  If you are a student,    you haven't finished your homework,  but you want to play the computer games first. At this time, your friend tells you that you haven't finished your homework yet. You should do your homework first. Then you will feel a little bit annoyed and say you don't have to tell me.