久违他心却未成他人
[jiŭ wéi tā xīn què wèi chéng tā rén]
Could translate into 'long separated from his heart yet still unable to forget him', which signifies longing and attachment toward someone who is already estranged. Even after a passage of considerable amount of time and significant change in status between each party involved, one has remained devoted to keeping the affection fresh, despite no chance turning into a real lover.