YOU SAID:

There's a bottle of mens shampoo in my... behind

INTO JAPANESE

私の中にメンズシャンプーのボトルがあります.後ろ

BACK INTO ENGLISH

There is a bottle of men's shampoo in me.

INTO JAPANESE

私の中に男性用シャンプーのボトルがあります。

BACK INTO ENGLISH

There is a bottle of men's shampoo in me.