change your tune

to change your opinion completely, especially because you know it will bring you an advantage
نظر خود را به طور کامل تغییر دادن، به خصوص به این دلیل که می دانید این تغییر، مزیتی/ امتیازی برای شما به همراه خواهد داشت
... [مشاهده متن کامل]

He was against the idea to start with, but he soon changed his tune when he realized how much money he'd get.