什么海誓山盟天长地久
[shén me hăi shì shān méng tiān zhăng dì jiŭ]
‘What about the eternal vows?’ It refers to people who easily say long-lasting promises such as ‘vow as deep as the sea, pledge as high as the mountain, and undying loyalty’. Here, the user is questioning how valid those oaths are in light of reality.