所谓天长地久所谓海誓山盟
[suŏ wèi tiān zhăng dì jiŭ suŏ wèi hăi shì shān méng]
This username plays on the traditional expressions of eternal love vows, 'Till death do us part' and 'I vow to you in front of the sea and mountain'. Both imply a promise to remain true until eternity. But this nickname uses the words ‘so-called’, suggesting skepticism about whether eternal promises can actually be fulfilled.