Great update! It's got me wondering if the MC is going to have an epiphany, where he realizes that he is starting down a slippery slope where he is in danger of becoming an abuser just like his father and Rachel? Father abused Rachel, Rachel abused him, now he in turn is abusing Rachel and Katherine. Hating Rachel is understandable (even while trying to find forgiveness for past misdeeds), but sexually abusing her while she is under the influence of the pills is still wrong. And while Katherine may want the MC to dominate her on some level, that doesn't mean the behaviour is okay, since he had no idea she was submissive when he started. Hopefully the MC realizes that if he's not careful he could become the monster, not the victim.