Maybe it's just me but I think it would be cool to see more realistic stepsibling fantasy scenes. We usually see fully grown actors extorting or bribing each other over teenager things like "I'll have sex with if u..." -don't tell mommy/daddy that I'm sneaking out to party, -give me a ride to the mall, -do my homework. Or stepsis is going on a date but never had sex so she asks stepbro to teach her. These are very common stepsibling scenarios. Meanwhile, some of the girls look like they're at least in their mid 20s and based on some of the male actors' bodies and arm hair, the men are probably in their mid 30s or 40s. I know it's just a fantasy, but I think it can be more interesting if they're in adult scenarios.
Like, a woman could be recently married to a good man who can't satisfy her, and then one day she visits her stepbrother she hasn't seen for years and who's also got his own issues with his gf and then one thing leads to another, and they have sex.
Or stepsiblings work the night shift together at a family-owned convenience store somewhere where there's very little customers, so to kill time they end up messing around in the break room.
Or stepsiblings are both lonely and have been unable to be in successful relationships, so out of desperation they agree to meet up once a month at a motel to release their sexual frustrations until they're able to find a partner. And then the sequel to that scene is that the sex is so good they continue to secretly meet up at the motel even after they find their own partners.
I think it'd be fun to see different scenes like those for taboo stepsibling fantasies. And with adult scenarios, you can freely cast actresses of any age and not worry about how weird they'll look still living and acting like teenagers.