微笑传染嘴角的苦涩
[wēi xiào chuán răn zuĭ jiăo de kŭ sè]
Translating as 'a smile infection causing the bitterness around the corners of my mouth,' this describes forcing a smile while masking underlying emotions of sadness or sorrow. A somewhat ironic statement showing emotional complexity where the appearance is joyful but the inside is suffering.