你是我的生活背景我是你的甲乙丙丁
[nĭ shì wŏ de shēng huó bèi jĭng wŏ shì nĭ de jiă yĭ bĭng dīng]
A metaphoric expression saying 'You are the background to my life and I am just another role-player in yours.' It conveys how someone feels minor or interchangeable while acknowledging their significant other’s larger influence.