I see.. well I am finding the game good so far. Its just a minor problem in terms of gameplay, but a pretty big one as far as immersion goes. Forcibly finger banging your mom/sis and making them blow you while they cry, without any sort of grooming or drugs, should be an extremely traumatizing experience that should drastically alter their lives. But next morning they are smiling and going "hey bro~"Keep doing it actually. Dakota stops talking with you and will always pull mom's attention off of you. The mom will also do the same thing.
Id be in favor of just not being able to rape them like that if making a more nuanced interaction at that stage of the game is a headache with little payoff.