Marge: Bart, I love you, but sometimes I don’t love your choices. (sigh) Now we have to find another school for you.
Homer: Yeah, and if you get kicked out of that one you’re going straight in the army where you’ll be sent straight to America’s latest military quagmire. Where will it be? North Korea? Iran? Anything’s possible with Commander Cuckoo-Bananas in charge.
cuckoo bananas is an expression usually said when something goes wrong or you make a certain mistake. Or simply just say the word because its fun saying it :P