Should I be offended?

So, I kick black guys out all the time. It's my job. They don't want to follow the dress code and our mang. has me kick them out.

The only thing I wish they would stop doing is calling me "nigga". I don't get it. I got called this at least five times last night. I'm a white guy with a shaved head. I'm also 32 years old.

I guess I just don't understand the terminology. If someone can explain this I would be very interested.

Just for the record. I'm neither "nigga" or your "nigga". Maybe calling me "nicka" would be better since my first name is nick?