It's rude to use the n-word when you're white.
Jim, who is white, is attending a rap concert and it's one of his favorite artists.
Jim wants to singalong.
One of Jim's favorite tracks is being performed, and he sings every word besides the n-word.
One of Jim's favorite tracks is being performed, and he sings the n-word at the top of his lungs.
The people around Jim see that he is being respectful and appreciate he doesn't say that part.
The people around him are shocked and offended by Jim.