ROYD-017 Living Together in a Cramped One-Room Apartment with an Unaware Big-Breasted Sister and Nowhere to Look

I live alone in Tokyo, and my life with my younger sister, Rika, suddenly started in my cramped apartment. Rika, who has suddenly grown into big breasts, is super defenseless at her house and is always in a dirty state, so there is no place to look at her! She couldn't stand it, so I forgot myself and forced myself to attack and even made a vaginal cum shot. However, that night she said, "I've been horny all the time..." She asked Rika for vaginal cum shot sex... We have a secret relationship that we can never tell our parents.