I have a pet hypothesis that, on average, those into step porn are more likely not have grown up with a sibling of the gender they fancy. I reckon those of us who did are more likely to repelled by anything alluding to incest.
People who grew up with ACTUAL hot step siblings notwithstanding.
Don’t care about the story??? My man…you’re missing out on the greatest epic tale ever told. It was about those lemon stealing whores!