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.
“People who watched porn in the 80s, were you really into plumbers or pizza delivery people?”
A man that brings me pizza, especially with extra sausage, may not automatically be my perfect partner but he’d be pretty up there.
Add a rug of chest hair I can wrap my fingers in…