"Nooooo!" He clutched the bag to him. "Not the cookies!"

It wasn't like he was really planning on not saying anything; given that the Library Aides Of Terror all already knew and were presumably on their way back, the cat was pretty much out of any proverbial bag it might have been trapped in.

Though it could be hiding in the cookie bag; maybe he should look in there. Even if there was just chocolate chip and no cat, it would still give him someplace to be hiding his face when he muttered, "SookayIkindofaskedhimout."