I ended up living with my brother and his wife. One day, he had an accident and saw Aika's sister-in-law's butt, and after that, [that] beautiful butt was burned into his mind and he couldn't let it go. My sister-in-law's butt that I can't take my eyes off of even in everyday life... One day, I reached the limit of my rationality and attacked my girlfriend's sister-in-law with all my might, making her ass vibrate as I watched her come to orgasm.