DS2 did this to a few of his pop-up books.

I tried the "help mummy fix the book thing". Hmmm... didn't work! He then proceeded to tear pages out of other books and brought them up to me and said, "oh no mummy, get the tape". Insanely cute but GRRRRRR!

He has 3 torn (much loved) books that live on top of the fridge now. He can see them and he wants them but he can't have them because he "tored them". Am I mean? Probably, but he hasn't torn once since the last one went up there and that was at least a couple of months ago.