Lethargic Sister Needs Help: Brother Gets Creampied!

My incredibly lazy older sister is a sight to behold—outside of her work shifts at home she barely moves! Everything is wrong with her routine; she’s so unmotivated that she owns barely two outfits for the entire year. Her slovenly appearance suggests no one would ever notice her existence. After five years of being single and overlooked by potential suitors due to her lack of dating experience (she's only seen romance in magazines!), things finally change when someone invites her out. She comes into my room asking to borrow a dating magazine but seems utterly preoccupied with food! Desperate to help boost her appeal before a date night disaster strikes again, I convince her to shop for new clothes. The next day is a revelation: she parades around in a tight-fitting bodycon dress that perfectly showcases her stunning figure. As she poses offhandedly, the slight hemline reveals a perfect T-back thong! My composure shatters instantly under her intoxicating allure. Before I even realize it, I’ve lost control, thrusting inside her and releasing an explosive cumshot deep within. To my shock, instead of screaming about Mom finding out, she beams! She doesn't just forgive me; she starts changing outfits constantly, asking for my honest feedback on each ensemble. She wants me to be her personal sex coach to build confidence for those upcoming dates. From that moment on, we sneak intimate sessions whenever Mom steps out—a secret affair that continues right up until they officially start dating together!