One choice is no choice. How about including options for players to choose from? For instance, when the MC helps his drunk sister to move to the bedroom, there could be options like (1-Hold her by the waist 2-Hold her by the butt) and when the MC has his sister drunk on his bed, there could be options like (1-Feel her ass 2-Lift her dress) and later (1-Spread her butt cheeks 2-Knead her naked ass) and later (1-Cum on her butt crack 2- Cum on her face) things like those. So players would have some control on what the MC does, it helps immersion.