Had enough of Stepmom for now?
Perhaps it's time to spend some quality time with Stepsis then?
Well...
Your stepsis hates your guts and has rule over the house while your dad and stepmom are out of town for the weekend. What's more, her girlfriend is sleeping over, so shut-eye seems highly unlikely as usual. How will you ever cope?
https://store.steampowered.com/app/1757760/My_Stepsis_is_a_Futanari