HUNTA-923 "What!? Thong?" My usually childish and unsexy sister is wearing a thong, making me fully erect! I can't hold back anymore and start high-speed piston thrusts on my sleeping sister...

One day, when I went to wake up my sleeping sister, I caught a glimpse of her panties from under her cute pajama pants! And upon closer inspection, it was a T-back! Doubting my own eyes, I slowly pulled down her pajama pants to confirm, and sure enough, it was a genuine T-back!!! My gaze was captured by my sister's ass, and I involuntarily got a full erection! Taking advantage of the fact that she was asleep, I played many pranks on her. But eventually, I couldn't hold back anymore and ended up inserting myself into her ass from behind! My sister didn't resist at all; in fact, she seemed to really enjoy it...