YOU SAID:
I sat on her and she sat on me
INTO JAPANESE
私は彼女の上に座り、彼女は私の上に座った
BACK INTO ENGLISH
I sat on her and she sat on me
INTO JAPANESE
私は彼女の上に座り、彼女は私の上に座った
BACK INTO ENGLISH
I sat on her and she sat on me
That didn't even make that much sense in English.