Man these bytches be sounding straight up racist. Hiding behind that n-word with the "-a" like it's their sole black friend.
Quick story: This girl I was dating aint from here. She black but from the caribbean. I use the n-word in casual conversation like every young brother I ever known. When my pops told me I shouldn't be saying that shyt AT ALL. I brushed him off like a lot of us younger dudes do. She wouldn't really say the n-word unless she was around other actual black americans and was trying to be down (Yellow Flag).
When we would have serious arguments, all of the sudden it was "N-word, you this!" or "N-word, you that!" And I would never say anything about it because I used that word all the time, but that shyt just wasn't hitting my ears right. The way she was emphasizing it was almost like a damn cracka. But I felt like I was tripping so I let it rock. One day she was going off and it felt like she was talking to me like a damn overseer or some shyt.

I stopped whatever we was arguing about and said "Yo look, That's a dub with all that nikka stuff. Stop calling me that fukking shyt." And she didn't argue she immediately stopped like she knew she was dead wrong.
I said all that to say, the age old adage "All your skin folk, is not your kin folk." is true af. Sometimes when other black people call you the n-word, they mean just that. To them you are a ******.