The "N" word

I am caucasion. I sit at a lunch table where I am the only white person. Everyone else is either, black, mexican, or native. They can all say the n word. For some reason, they let me say the N word, as long as i say it properly. I don't wanna say it like a whiteboy, they don't like that. I have to say it how they say it, like a greeting or a normal word. I can't say it ending with "ER" or they'd probably kick the s-hit out of me. well they probably wouldn't because we're all friends but they'd get pretty p-issed. something i like to do is use slang word's from gangsta hip-hop in a very white person accent. they wouldn't like. if i said it seriously it would b all good. i can say "what it iz my n-igga" or "whaddup my n-igga" but i can't say "greetings, n-igger" lol most caucasions are not allowed to say it or they would get their a-sses kicked