My little sister's breasts keep growing bigger every day, and she's troubled by their size. As she moves around the house carelessly, her breasts constantly brush against her arms, drawing attention to them. The sensation unconsciously makes my dick hard, and when she notices, she jokingly says, "You're turned on by my breasts? Nothing good will come from this. But here, I'll give you my breasts—do whatever you want with them." Tempted by her words, I start sucking and groping her big tits, and gradually, she begins to get excited too. This story captures the deepening intimate relationship between the two siblings.