Plz Dont Get Offended

So I was sitting in Chem class ealier this week and I was some what .....oh what shall we call it..... oh heck we call it what it was I was ashy. Well actually I was Very ashy but n e way I asked my friend if she had some lotion. And she was laughing cuz I was so ashy. And then she looked at her hands and were like oh I'm ashy too. Well she is white and I am black so we looked at each other and just started laughing. So we put on the lotion. And this kid next to her was talking about the D and how it was all rough and ghetto. And when close minded ppl start talking I block them out. Well the conversation turned from being close minded to being flat out racist. No one used the N word or anything but there were jokes made. And yes they sat there and looked at me like is she going to say something. Just as I was bout to open my mouth and say what I had to say my friend who I was just laughing with about being ashy turns to me and says I have a joke but Ash plz dont get offended. Rite then I knew it was going to be racist. So she says her joke (which I didnt find funny) and her and the other people at the table start laughing. I looked at her and said did you really just say plz dont get offended. And she was like well it was not to directed at you personally. And I believe thats where I lost my kool and went off. I said what do you mean it wasnt directed at me personally. You just insulted my culture, my race, my ancestors not to mention a number of other things but I am not suppost to take it persoanlly. Then plz explain to me how I am suppost to take it. She sat there with her mouth open and not saying a word. And I said my point excatly. I moved away from the table and have not been back. I think the thing that hurt me the most was not that they were telling racist jokes or even that they were closed minded but the fact that one of my friends had the never to look at me say plz dont get offended and then tell a racist joke. I am hoping she will understand my pain and anger and well.......no get offended!