As a bit of background, DP and I have been together for 2 years. DP is white English.
DP and this guy, let's call him L, have been friends since pre-school. We are all in our early 20s now. They were best friends throughout secondary school, but drifted away when DP went to sixth form and uni and they rarely spoke to each other or met up. But DP's parents still refer to L as DP's best friend.
About a year ago, DP went to the pub with his football team, and L was there. One of the guys was making conversation with DP and asked where I was from. L then buts in and says 'p*'. For reference I am not Pakistani but I am Asian, so no-one can pass this off as anything other than a horrific racial slur. Bare in mind, I had not even met L at this point, he used a racist term against someone he had never met and had done nothing wrong to him.
The whole football team said 'you can't say that' to L. A few days later, DP sent L a long text basically saying it was wrong of him to call me a p*. L sent a text back apologising (I am sure he didn't mean it. You will see why I think he didn't mean this below. He was just afraid to lose DP as a friend as he barely has any friends as he is shy).
Fast forward just under a year. I meet L at a pub gathering. L ignores me, he didn't even say hello. It was very awkward because this was the first time he was meeting me, and he had already sabotaged that meeting by calling me a p* previously.
I meet L again at a birthday party. This time, it all kicks off as L referred to another of DP's friends as a p and I said 'you can't say that, that's very offensive'. L apologises for calling me a p previously (I accepted this) but his girlfriend ruined everything by trying to make excuses for him, saying 'he meant Pakistani' (this is BS as I am not even Pakistani) and was getting very aggressive, coming right into my face and shouting. L does not do anything to stop his girlfriend. To add insult to injury, L used the p* term again about the same friend.
Tonight, DP is going to L's sister's birthday party (he is not friends with L's sister, he is only going because the parents are family friends with DP's parents) and it has riled up my feelings of anger again. I can't understand why DP would want to continue talking to L and being friends with him when he called me a p* and has continued to use the term against others.
I suppose I wish that DP stood up for me more by cutting off all friendship with L when he originally called me a p*.