Giving dumb blondes a bad name, ultra-pregnant JESSICA SIMPSON turned her world upside down when she had an early morning Mac-Attack, ordered fiance ERIC JOHNSON to whip into the drive-thru of an LA McDonald’s, and told the window gal: “I want something from your lunch menu.”

Gal: “I’m sorry, but it’s 8 a.m. and we’re only serving breakfast.”

Pondering the menu while cars idled behind, Jess finally blurted: “Well, do you have anything on your breakfast menu that tastes like lunch?”

Totally gob-smacked Gal: “Maybe you’d like one of our egg sandwiches?”

Jessica (whining): “Nooo, I really want something off your lunch menu.”

Gal: “Uh, please pull to the side and think about it!”

Snapped Jess: “Oh, forget it. This is so complicated – we’ll just go somewhere else!”

Frazzled boyfriend Eric mouthed “Sorry” to the female order taker, put pedal to metal and split with Baby-Momma!