One should always remember the inability of the under-fives to keep a secret. It is my mum's birthday today and last night I overheard the following exchange between her and Tom at bedtime:
Tom: Can I come to your birthday party?
Mum: We'll have to go and get a cake.
Tom: But we've got you one.
Hmmm, I'm sure I mentioned the cake was a secret. Lesson learned!