Having a big-breasted sister means I get teased by friends every day with jokes like "Your sister's tits are huge lol" or "What cup size is that lol." I always reply with "Stop it lol, I don't care about her boobs or anything lol," but in reality, I'm having frequent sex with my sister at home, passionately groping and squeezing her massive K-cup breasts. She doesn't mind it at all—in fact, she's the one who keeps begging me daily, saying, "I want it... please..." As her breasts continue to grow, her sex drive gets stronger and stronger, and honestly, it's becoming hard to handle. ※Recommended viewing positions: sitting on chair → sitting on floor → kneeling → lying on back