说不清道不明的关系猜不透忘不掉的感觉
[shuō bù qīng dào bù míng de guān xì cāi bù tòu wàng bù diào de găn jué]
Describing 'an indefinable yet unforgettable relationship.' This hints at an intricate bond where emotions aren't fully clear or easily expressed—a kind of complex, memorable attachment between two people.