我愿当你反复利用的匕首
[wŏ yuàn dāng nĭ făn fù lì yòng de bĭ shŏu]
A metaphorical and poetic sentiment where 'willing to be your dagger that is used repeatedly' signifies a willingness to be at someone's disposal or be utilized when necessary, regardless of possible damages to the person themselves. It's like a self-denial yet full dedication of loyalty, which can be seen as strong emotional dependence or selfless devotion.