YOU SAID:

Behind my behind lies someone's underwear under the bed cushions.

INTO JAPANESE

私の背後には、ベッドクッションの下にある誰かの下着が横たわっています。

BACK INTO ENGLISH

Behind me, someone's underwear under the bed cushion is lying.

INTO JAPANESE

私の背後には、ベッドクッション下の下着が横たわっています。

BACK INTO ENGLISH

Behind me, underwear under the bed cushion is lying.

INTO JAPANESE

私の背後には、ベッドクッション下の下着が横たわっています。

BACK INTO ENGLISH

Behind me, underwear under the bed cushion is lying.