I passionately penetrate my reserved stepsister and demonstrate that I am not homosexual, ultimately ejaculating on her buttocks - Part 1

In an attempt to prove my heterosexuality to my family, I invite my stepsister over for a steamy encounter. Despite her initial hesitation, I manage to satisfy her cravings and mine as well, culminating in a passionate climax on her backside. This marks the beginning of our twisted, taboo relationship.