If I had to choose any of the sister's bed's to sleep/fuck them in it would go in this order
1) Amy
2) Laura
3) Sarah
and if I had to choose between Sarah and Shasha I myself would always choose the later.
Cause no offense to Sarah I just like Shasha more, and besides knowing BON he is eventually going to make it where the Mike our main male is able to get balls deep into Lucy so if I want the full blooded incest I would go for Lucy over Sarah (unless of course Lucy ends up somehow getting tied in with Sarah)
But it does not seem strange, that Mike does not look anything like Lucy and even the father has black hair?
And Mike is almost blonde .. (would be a way in case Mike choose Sarah and the story does not end in incest)
That Sarah and Lucy are relatives is more than obvious ....
Mike commented that he does not remember his mother .. (dialogue with his aunt) and did not recognize Lucy in the laboratory quest .. and in the photos on the pc ..
Well, the story is far from over and the author is free to change at any time ..