My apologies if you already addressed this, but would you ever consider calling a white person "my n*gga"? (I know this seems like a dumb question, but given the circumstance.. I am curious.) What if that person were your best friend? Or would that term still only be reserved for an African-American friend of yours? If so, then I must ask: why choose a word that denotes race, especially if it serves no purpose in the immediate context?
All the black people down here say it to everyone, regardless of race