From Ta-Nehisi Coates:
White people who actually spend time around black people--not black individuals whom they know from work, but black people with their families, in their communities, with their parents--will quickly notice that using "nigger" actually isn't a barometer of closeness. I'm black and I don't call even some of my best friends nigger. They, unlike me, are offended by it. Black humans, like most humans, are different from each other. But to grasp this, you must have to have relationships with black humans that go beyond your job.
Ta-Nehisi, mon pauvre frère !