你的空欢喜
[nĭ de kōng huān xĭ]
'你的' (nǐ de) means 'your' ; '空欢喜' (kōngxǐhuān), literally “Empty Glad” or unfulfilled joy; altogether 'An Unrequited Love/Crushing On Someone'. As such, expressing longing towards something out of reach while feeling bittersweet emotion due to such longing.