This pisses me off!
When used by someone of another race, the N-Word is extremely offensive to a black person. Where my dad grew up, you would get the ass-whooping of a lifetime for saying that to an African-American.
I don't condone ANYONE saying it (I never do; I'm black), BUT, the racial significance of using the word is greater when used by another race.
The Black Civil Rights Movement deemed the word to denote racism AND ONLY racism. Using it, or any form of it, IS RACIST. So don't call me racist for telling him not to use it.
If he's not black it's much worse. We African-Americans generally don't have a problem with being called it by one another. That is because, the underlying meaning of the word makes it impossible for it to be derogatory when a black person is called the n-word by another black person.
Do some research on the topic and get educated. It is completely racist and inappropriate for a non-black to use that word, ESPESCIALLY when directed at a black person.