姑娘那么美不适合流泪少年那么帅不适合吸烟
[gū niáng nèi me mĕi bù shì hé liú lèi shăo nián nèi me shuài bù shì hé xī yān]
It indicates that pretty girls shouldn't cry while handsome boys shouldn't do unhealthy or self-harming activities like smoking, reflecting the speaker's ideal views about beauty and youthful behavior.