YOU SAID:
my girlfriend cheated on me
INTO JAPANESE
私のガールフレンドは私をだましました
BACK INTO ENGLISH
My girlfriend fooled me
INTO JAPANESE
彼女は私をだましました
BACK INTO ENGLISH
She cheated me
INTO JAPANESE
彼女は私をだましました
BACK INTO ENGLISH
She cheated me
You've done this before, haven't you.