Dyed-in-the-wool blonde JESSICA “Is it chicken?” SIMPSON just told a galpal the secret that made her belly look flatter until that baby bump practically exploded out of her shirt – pieces of cardboard that are now stashed in her undies drawer.

GUY QUESTION: “So why’s she got ’em stashed now that the bump’s too big to hide?”

LADY ANSWER: “Because she’ll be up to her old trick of stashing them under her Spanx to look slim again right after the baby pops out, doofus!”

But…uh, why save the OLD cardboard – waste not, want not? C’mon!

(ANSWER TO ALL DUMB QUESTIONS: Jessica Simpson!)