I think it happens in the book most with Corey's mom. What makes it subtle and cleverly done, I think, is that since the story is being narrated by the twelve-year-old girl, who often has lighthearted one-on-one conversations with her mom, her mother makes these funny remarks that are over the narrator's head but that we as the reader can appreciate.
I think this is my favorite line in that regard. It is in page 178 of 449 in my copy of the book:
Meg Kimball wrote:[Corey asks] "Hey, wait just a minute. What did you mean about me having a gullible side? Is that a bad thing? What does it even mean?"
[Corey's mom answers] "Well, no one's really certain what it means, sweetie. For some unknown reason the word 'gullible' is not in the dictionary."
Did you catch any of these? If so, which is your favorite?