Secrets

Chances are, it is safe to tell Ian your secrets:

Ian:  Mom?  Do you know what Gaga is getting you for your birthday?
Me:  No, I don't!  She didn't tell me!
Ian:  Well, I know.
Me:  Ian, what is Gaga getting me for my birthday?
Ian:  I can't tell you, because then it wouldn't be a surprise.  Plus, I forgot.  So I will not tell you AND I forgot what it was already.