Can't (or don't) Judge a Book by Its Cover expression phrase
Said to show that you can't tell what something or someone is like by looking at their appearance only.
A: She doesn't look very intelligent. B: Come on! You can't judge a book by its cover.
My father used to tell me,"Don't judge a book by its cover".
If a person "gets a lot of grief from someone", he or she receives a strong criticism or judgment for something.
Used to say that someone makes a judgment or forms an opinion from something.
The phrase is used since the early half of the twentieth century.
Friendships will develop well and be successful when the friends respect each other's privacy.
You should respect your friend's privacy. A hedge between keeps friendship green.