Manipulation Quotes in We Need to Talk About Kevin

How we cite our quotes: (Chapter.Paragraph)

Quote #7

You'll just have to take my word for it—I know you won't—that when you weren't home, Kevin was sour, secretive, and sarcastic. (19.23)

Eva spends more time with Kevin than Franklin ever does, but why doesn't Franklin believe her? Is he inclined not to believe her, or has Kevin completely wrapped his dad around his little finger?

Quote #8

Then he stopped, right under the mirror ball, having correctly calculated that Alice's next pirouette would land her left ear exactly in line with his mouth. There. Contact. He leaned, just a little, and whispered. (20.135)

Eva witnesses this terrible scene at the school dance. What starts out like a romantic comedy concludes with the exact opposite result—total devastation. And that was surely part of Kevin's plan the entire time.

Quote #9

Me, I recognized too well the mark of deliberateness about these efforts—so this was trying to be a good father—but I doubt that it looked to Kevin like anything other than surfaces would suggest. Clearly his little sister's injury had won her only more doting. […] I thought, Didn't our little stratagem backfire? (23.165)

If Kevin's plan to manipulate his parents using Celia backfired, what was the original intent?