我要疼你一辈子我要赖你一辈子
[wŏ yào téng nĭ yī bèi zi wŏ yào lài nĭ yī bèi zi]
It means the user is vowing lifelong affection ('pain you with care forever') and dependence ('stay on you forever') toward someone, indicating dedication to a deep romantic or familial love.