The MC is a teenage boy living with his Mother and younger sister. I don't remember anything about the Father. The scene that sticks out in my mind, the MC cums between his best friends mothers legs while riding a pool inflatable in a "jousting" game.
It was maybe a year ago on PC and it was 3D. The MC , his friend and his sister were portrayed as young teens (like 15 or 16). The mothers were typical large breasted Milfs.