傻瓜一生只为你笨蛋一世只爱你
[shă guā yī shēng zhĭ wéi nĭ bèn dàn yī shì zhĭ ài nĭ]
It's an endearing and playful way to express unconditional, lifetime loyalty and affection toward one specific person. Translated literally as 'A fool all my life only for you; a dolt for you forever'.