JUMP-4031 My brother is my masturbation pet #5. Kotone-chan

Kotone-chan, a cute girl of her age, has a helpless pervert brother who hides in the house all the time and peeks at Kotone-chan masturbating and having sex with her boyfriend. One day, I sneaked into Kotone-chan's room and tried to crawl at night, but it was found out, and from that day on, my brother turned into my sister's slave, and it seems that my sister is forcing me to do cunnilingus like a daily routine. I say no, but I have this older brother and this younger sister!