This was related to me a couple of days ago. I laugh every time I think about it.
An Asian coworker went to a party over the weekend; virtually all of the guests as well as the host were also Asian, although there were a couple of nondescript white people in attendance, which included a couple of girls who apparently crashed the party.
At one point the host lifted his drink and offered a kind of all-in-one toast, "Merry Christmas, Happy Holidays, Happy Hanukkah, Happy Kwanzaa".
My coworker, sitting near him, said, "Dood, look around. Who are you wishing happy Kwanzaa to? No one here celebrates Kwanzaa."
At that point one of the crashers said, "Well, I celebrate Kwanzaa, I'm a Jew."
Somehow my coworker managed not to fall over laughing; I don't think I'd have even tried.