That's it really. My neighbour's boy told her that parents buy the presents. I was there for the conversation and changed the subject, and gave it no attention. I also had violent feelings towards the boy 
So. What will I do? I know DD at 7 years will think, and so be it, but I am absolutely not ready for my 4 yo to not believe.
Will I do the Elf thing? A letter from Santa? We have no tradition of this kind of thing in our house so I'm a bit unsure, and I don't want to make them more suspicious.
What will I do?