我爱的少年他无情毒如蝎
[wŏ ài de shăo nián tā wú qíng dú rú xiē]
'The youth I loved is heartless just like the venom of a scorpion.' In short, it describes unreciprocated love where one side feels all emotions and passion while the other side shows no compassion, which hurts more than the pain from venom.