背せ中なかを流ながす

expression, godan verb (-su)

rinse someone's back

Used when washing someone's back, typically in a bath setting. Often implies helping someone wash their back, or asking someone to do so.

• お風ふ呂ろで父ちちに背せ中なかを流ながしてもらった。

  I had my father rinse my back in the bath.

• 背せ中なかを流ながしましょうか？

  Shall I rinse your back?