YOU SAID:
I didn't know you foisted yourself!
INTO JAPANESE
私はあなたが自分を欺いたことを知らなかった!
BACK INTO ENGLISH
I did not know that you deceived me!
INTO JAPANESE
あなたが私を欺いたことを知らなかった!
BACK INTO ENGLISH
I did not know that you deceived me!
That didn't even make that much sense in English.