YOU SAID:
I slept with my best friend's brother.
INTO JAPANESE
私は親友の兄と一緒に寝ました。
BACK INTO ENGLISH
I slept with my best friend's brother.
INTO JAPANESE
私は親友の兄と一緒に寝ました。
BACK INTO ENGLISH
I slept with my best friend's brother.
That didn't even make that much sense in English.