My Sister Is a Doting Brother Fanatic!

What is it like to have a domineering sister? That is, if my eyes stay on any product for more than three seconds, the sister next to me will say: "Buy it!" Me: Hey, sister, what kind of car was that that just passed by? Sister: Buy it! Me: The clothes on that person are really cool. Sister: Buy it! Me: This building looks really impressive. Sister: Buy it! Me: That girl is so pretty... Sister: You're tired of being a brat, aren't you? Don't buy this! Me: Sister, I will use the money you gave me to buy your time. Can you please not leave? Sister: Brat, I can't buy this... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.