Could you date a man that has friends that use the "N" word?

I am dating a wonderful man. I also have a beautiful granddaughter that is bi-racial. Sometimes when we are out in a group of people they will use the "N" word around me. Now keep in mind they can't look at me and tell that my granddaughter is "mixed" I usually ignore it as people can be ignorant and I don't want to sit there and say "you know my granddaughter is mixed" so what would you do under these cirstances?