嘟着嘴闷闷不乐咬着唇不知所措
[dū zhe zuĭ mèn mèn bù lè yăo zhe chún bù zhī suŏ cuò]
Translated as 'Pouting Unhappy, Biting Lips Feeling Helpless', it depicts a somewhat helpless state, indicating that sometimes one feels unable to do anything but can only stay unhappy.