少年姑娘凉心少女少年心疼
[shăo nián gū niáng liáng xīn shăo nǚ shăo nián xīn téng]
It conveys the complexity of teenage relationships and feelings: a young man makes a girl feel heartbroken (literally translated as her heart becomes cold), which conversely means he feels heartache for her pain; there's a circular empathy here that is uniquely captured in Chinese expressions.