嘴角那一抹淡淡地苦笑
[zuĭ jiăo nèi yī mŏ dàn dàn dì kŭ xiào]
"A Faint Bitter Smile At The Corner Of The Mouth" This represents an expression of hidden inner grief and sadness. Sometimes the smile is used to mask real emotions and pain inside the user, which may suggest a bittersweet mood or experience.