ZMEN-010 Thinking she was his girlfriend, he immediately started pounding his sister's pussy! He realized it during internal ejaculation!

I, with my insatiable lust, was captivated by her defenseless ass and wanted to fuck her without even looking at her face. So I immediately inserted myself and pistoned away, using her vagina as a mere hole for sexual release. As I thought 'Ahh, that felt good,' the hole I thought belonged to her turned out to be her sister! This is bad! It should have been a fatal situation, but she said, 'Keep it a secret from my sister and do more...'