This is an awkward question, and Cade knows his answer will be stupid, but he also feels beyond a shadow of a doubt that he is right. It's the same way he knows that he likes sweets and that the Maker is real: it's just a fundamental truth.
Because if it weren't, why would it be so shameful?

"It's... no, it's just..." He fidgets. "...wrong."

If it were right, he wouldn't have been begged to keep it a secret. It wouldn't have felt so threatening.