I'm probably in the minority here, but I'm fine with neither the mother or the sister being LI. Frankly they haven't been developed as such (maaaaaybe the sister, but certainly not the mother) and there's already too many love interests to properly work with. It's going to slow the development pace and make for shallow gameplay. Wouldn't you rather spend more time dominating Piper after she pushes your buttons? Fuck her ass to teach her a lesson about being a little slut. Convince Eliza you're the real deal and you (and the baby you have swelling her belly) can be all the family she needs. Or show Torrie she doesn't need to be the only girl in your life, and maybe just maybe the more (girls) you hook up, the better it gets.
In short, if the Dev WANTS to do incest with the sister (or mother) then that's their vision, but the game is already sexy as fuck without it and I'd rather see those work hours go towards deepening the work rather than expanding it.
