The word "nigger" is totally unacceptable and totally offensive to people of colour in both Great Britain and USA. It should never be used lightly and certainly not as a throwaway comment. It's not just a matter of political correctness, it is like "queer" or "kike", beyond the pale.
Such great shows as Gilbert and Sullivan's Mikado have had the word excised from modern productions even though no one has accused the composer or librettist as being racist and the show could be seen as being of a time when the word was widely used. Even a show with a message of tolerance such as Jerome Kern and Oscar Hammerstein's showboat which was recorded by John McGlinn in an authentic version some twenty years or so had major problems when it tried to use the word.
So please, never ever use that word as a term of derogation or abuse on this or any other posting