Telling other peoples kids that Santa isnt real.

This is not a post asking about whether or not your family does Santa, Easter Bunny, etc. Every family does their own thing and that's kinda another conversation.

I am only wondering if you think adults who aren't a child's parents have the right to tell that child that Santa/Easter bunny isn't real? So say your family doesn't do Santa, do you feel like it's okay to tell other peoples' kids that he doesn't exist?

So today I filled in for my mom who was supposed to chaperone a field trip for my youngest brother. It's a kindergarten class so the children are ages 5-6ish. A kid in our car was talking about how excited he was for the Easter Bunny when the other adult with me turned and started telling him all about how the Easter Bunny and Santa aren't real. I tried desperately to change the subject but of course all the kids we're stuck on this topic the rest of the 20 minute drive. I really pushed the "talk to your parents about it when you get home" agenda with a little success. The other adult in the car was upset I didn't "back her" saying "if parents don't want to educate their children then other adults should". Do you feel like outside adults should comment on things like that to children who aren't theirs?