is it my incest fetish or is the mc ment to be related to thes girls. some dialg just seems to fit into a incest patch formula.
The MC is not related to anyone. But they feel pretty close to each other (Annie because of the long friendship and Nancy because she took care for him when he was younger, same with Penny and Dalia). Obviously this does not apply to Luna, Nova or Alex, since they were met during the time the game takes place.
And IMO it is good that there is no incest involved (yet, I am pretty sure that there will be incest between Nancy, Penny and Dalia in form of three- or foursomes). Because if you would make Annie the sister, you would somehow make her more important than Nancy, Penny or Dalia. And if those were the actual family, it would put Annie lower.
So I think the relationships for the game are just perfect, and this is coming from someone who is a huge incest-lover.