Initially saw this and did a double take at the art style. Hungry Dragoness was a great game. This seems more like a scene collector, sadly, but the art is still high quality.
I read the title and thought you were talking about something like the classic Japanese anime "but they aren't actually siblings" trope, but you're talking about shoehorning step-family relations to cater to a fetish. Yes, the latter absolutely kills the vibe and often makes no sense. Like...