M.D.
Most likely he already knows... but won't tell you.. I think usually around 1st-2nd grade they find out from their friends. I remember my middle son was in either the 4th or 5th grade and was tired and in a bad mood. I don't remember all the conversation but he was pushing my last nerve and and I said something to him like "What, do you really think there is a tooth fairy and Easter bunny"; and with a serious sad look he said, you mean they aren't real? Then months later we were talking and he said he already knew but he as mad at me... I really thought I burst his bubble... My parents would hide most of our presents and when we woke up on Christmas morning the tree was full of them until I left home...