你是我患得患失的梦你是我可有可无的人
[nĭ shì wŏ huàn dé huàn shī de mèng nĭ shì wŏ kĕ yŏu kĕ wú de rén]
It translates to 'You are my obsessive dream; you are the optional part of my life.' This expresses someone who is important enough to haunt dreams but whose absence doesn't matter much.