My sister who lives under the same roof has a well-developed ass. I couldn't be happier. That's why, ever since she was little, I (you) have been giving her a special education. My sister does her best every day to train her ass without questioning anything. I also use my dick to make her aware of her body axis, and I want to shake and rub her ass to make the best ass meat. Please support her training with all your might.