羽はねを伸のばす

expression, godan verb (-su)

let one's hair down; relax and have fun

Used when someone unwinds and enjoys themselves freely after a period of work, stress, or restraint. Often implies a temporary escape from daily pressures.

• 週しゅう末まつは友とも達だちと温おん泉せんに行いって、羽はねを伸のばした。

  I went to a hot spring with friends over the weekend and let my hair down.

• 試し験けんが終おわったら、思おもいっきり羽はねを伸のばそう。

  Let's really let loose after the exams are over.