笑得沒心沒肺哭得撕心裂肺
[xiào dé méi xīn méi fèi kū dé sī xīn liè fèi]
This name translates to 'Laughing Without Care, Crying in Painful Anguish,' depicting extreme emotions swinging from laughter to deep crying. Such an idiom shows how the speaker may be emotionally vulnerable and prone to sudden shifts in mood between intense happiness and deep sadness.