I'm going to call my best friends gf racist
Oh no, I cannot imagine why you would do that. Is there a reason why you want to call your best friend's gf a racist?
She has an ugly black face, she also has a stinky fart
If you call her racist for no appropriate reason it will likely make her upset. Plus, you will jeopardize your friendship because your friend will most likely back up his girlfriend.
She has a stinky fart. And she's ugly
There is no reason at all that you can call someone racist and them not be upset. You will cause a lot of hurt if you do this.