I see now what the argument is about. I agree that the curse should be in Kryptonian, but I think it would be funnier if it was like the English gibberish that was written earlier:
"Yer--yer pahkutlent," said Lois, "pahkutlentin thuhpahkutzuv loyers."
Dhupahkut zev? Nor winced at the crude reference to his mother's eating habits.
I think that would serve both your purposes because it would seem more likely for Lois to accidentally hit a curse when she was saying a string of words--and for it to be very close, but not exactly the words. And as readers, we would enjoy her accidentally stumbling on a real curse in Kryptonian when she was trying to curse him in English.
Just a thought.
