Being socially acceptable has nothing to do with needing a vagina to reproduce, red. You're a human, and you live in a society with other humans. You should be respectful towards other people no matter what their race is, and mind your language, especially since there's a few words that can offend other people.
You cannot blame someone for being offended, you cannot blame me for being offended, and you can NEVER justify using such rude language especially when speaking in the presence of other people who might be offended by it. This is not a matter of 'my friend is black so its k' or 'black people are free today so its k' or 'im white ur black we should be equal stop provoking anger you ni**er'
You cannot blame someone for being tribal, just as you cannot blame someone for not liking you because you're a certain race. However, you can blame someone if they openly advocate and make it clear that they don't like you, in a manner that you might get offended by.
There is never a good reason to offend someone intentionally, unless you have a mental disease and your life is built around making others unhappy. If that's your life, then I wish you good luck being a social human being.