MIDA-389 I accidentally witnessed my NEET, depressed sister masturbating and lost all reason. She came but didn't notice as I pounded her like a madman. Nana Yagi

"I saw it…." — My sister's room is messy and dirty. She has been wearing the same lame t-shirt since middle school. She looks at her smartphone all day, and her eyesight is bad. On top of that, she's a shut-in NEET. A typical rotten girl... Of course, since we're siblings, I have no interest. ――My sister was seriously masturbating! At that moment, my sense of morality, ethics, and reason collapsed with a sound. I became a sex monster for my sister! My sister's dry, mourning pussy also awakened! I kept repeating vaginal penetration...