旧人心凉良人心酸
[jiù rén xīn liáng liáng rén xīn suān]
The phrase 'Jiu Ren Xin Liang Liang Ren Xin Suan', translating into the heart of the ex has grown cold while the kind-hearted suffer from it, conveys sorrow over someone whose relationship cooled down, which makes others feel heartache and sadness on their behalf. This can imply feeling abandoned or left alone.