你长年冷淡不苟言笑我满脸欢颜长叹流年
[nĭ zhăng nián lĕng dàn bù gŏu yán xiào wŏ măn liăn huān yán zhăng tàn liú nián]
This nickname reflects a deep contrast between two individuals, where one person is cold and never smiles while the other shows happiness in reminiscing about their times together.