I still think you're one of the best writers for this genre on this platform, but I gotta say that the level of corruption coming from the sister got a bit too much for me this update. The sister is a horny beast and I've enjoyed that a lot throughout it unfolding, though it seems like that aspect of her peaked to a point where her morals towards her family are completely overthrown by lust and a need for control. What she wants, she gets and she doesn't really care how it's done, as long as it happens. I enjoy that type of personality in these stories when the girl can be described as something along the lines of a spoiled brat, but the sister in this story goes beyond that and starts leaning towards a sociopathic mind. I can imagine her character arc being the holy grail for corruption enjoyers, but it's all a bit more than what I'm looking for personally.
I didn't like that the sister chose to be the puppetmaster of the already unfolding relationship of her mother and her brother. It felt like she had to convince herself of having the upperhand, so she could avoid her feelings of jealousy and in turn replace that with lust & power. She understood there was no stopping what those 2 felt for eachother, so she could only let it be as long as it was under her watch so to say. I was really hoping the mother would go through her feelings of desire on her own terms, but with this behind the curtains power dynamic going on, I feel her processing of it is being orchestrated too much and too intense. It has brought her guilt to the point of getting blackout drunk, which results in some form of guided threesome with an undertone of rape. With this scene, this novel turned from exactly what I've been looking for, to exactly what I've been avoiding on this site. Since the conclusion of the last update I was already kinda expecting you to go for the style of corruption you implemented for the sister, but I was convinced things would be escalating just a bit later on in the story. My expectation for this update was the mother's limit to be reached and some drinks giving her the boost to pick up where 2.4's teasing ended. If you'd ended the massage with a m/s handjob scene, including the nosy sister peeking, I'd have been a VERY satisfied fan. The entire buildup of that scene seemed to be aiming at that, but it's almost as if while you were in the middle of making it you lost your shit and said: "fuck it... MORE!!!"
To end my review, let it be known that my takes on this aren't targeting your writing skills, it's purely from me being a bit more vanilla regarding corruption. I'm 100% sure you made a whole lot of people very happy/horny yesterday. I'll still be checking in for the future of this project, but I'm not expecting it to be THE project for me. Good luck on your progress and remember to keep having fun with it!