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.
Well of course you would. You paid for a search engine. You’re gonna justify that any way you possibly can. There are other free search engines out there, you know.