what will you do when your idea is contrary to your father's idea

Tweet

I live with my parents. But today, my father give a idea to buil one room extra in our house and I don't agree. Cause of that room will be very small base on small money to buil it. I have no contribution to build that room, so do I need to change my father's opinion? And also I don't want my father to hate me when I prevent him from building that room.