Last night my DS was on my IPad looking for ideas for his Christmas list. He had been asking for a Wii U for ages and I had convinced him it wasn't an option as it was too expensive, but I had actually bought one as a surprise.
He was looking at the Wii U games on Amazon, and looked at Mario Maker and He noticed across the top of the page a banner saying 'you purchased this item on 1st Dec' so he has now worked out that I must have bought him the console as I have bought a game. ----
I know it's my fault that I hadn't logged out of Amazon before letting him use my iPad, but I thought I would warn you just in case your DC are browsing Amazon - Don't forget to log out of your Account first !
I mumbled that he must have misread what the banner said (after I hastily logged out of my Account !) but I think he has guessed what his main present is. Such a shame, as I haven't bought much else as the main present was so expensive.