I agree with everyone saying that DS doesn't know how to write an incest game, but I also think that he doesn't have a clue about BDSM either. We've yet to see any good BDSM being played out. So far all it's been so far is;
Alice/Kate: "I'm in control."
Max: "Okay"
That's barely even submission. And how on Earth does a sub magically turn into a dom, then straight back to a sub?
Also, from what we've seen from mum, there's no real BDSM in play. From what we seen in the movie all she gets is a light spanking with a ruler. I don't know about you, but when I think about BDSM I think of leather, being chained up, whips, torture, pretty much ZERO fucking etc. Am I wrong?