I am struggling with this. My oldest boy is 8 and very smart. He doesn't go to public school, but interacts with kids in cub scouts, etc. I don't want him getting made fun of because he might still believe in Santa. I kind of think he has it figured out (but is not completely sure), but I also have a 6 year old daughter that still loves the idea of Santa Claus.
Did you sit them down and tell them - did they hear it from someone else - if so, at what age??