Recently I've gotten a few of my friends into UC Gundam and I have started joking to one of them about Yazan being Jewish and claiming that some fans call him "Yazan Dreidel." My friend believed me. Me and another friend pushed the joke further saying that this was revealed in a Gundam Christmas special aptly named "Char's Christmas Attack." Again, he believed us, and me and the friend that's in on it keep pushing the joke further. We're almost done watching/rewatching Zeta and are about to move onto ZZ and I'm afraid I'm going to break his heart when we have to tell him that the Christmas special was a joke.
TL;DR: How do I tell someone that Santa doesn't exist?