YOU SAID:
ethan was eaten by sam's sisters' husbands
INTO JAPANESE
イーサンはサムの姉妹の夫に食べられた
BACK INTO ENGLISH
Ethan was eaten by Sam's sister's husband
INTO JAPANESE
イーサンはサムの妹の夫に食べられた
BACK INTO ENGLISH
Ethan was eaten by Sam's sister's husband
That didn't even make that much sense in English.