看见你和她我只能强颜欢笑
[kàn jiàn nĭ hé tā wŏ zhĭ néng qiáng yán huān xiào]
'kan jian ni he ta wo zhi neng qiang yan huan xiao', meaning 'seeing you with her all I can do is put up a smile'. Depicts putting up false happiness when confronted with situations where others appear to be happier without noticing one's own pain or struggle, emphasizing forced positiveness amidst personal distress