This pretty much killed my mood for the next half hour and made it impossible to focus on the dancing. No matter what retorts I came up with, I was just really disturbed. I know xenophobia has been part and parcel of American culture for ages, but this was really out of nowhere and quite disturbing.
PS: Suddenly had a vision of myself walking down the street in elf ears and having her say, "Go back to your own planet, you stinking Vulcan!" - which made me laugh, especially as I could easily imagine this person getting confused about real versus imaginary places.