The game clearly displays a dysfunctional relationship at the moment. Multiple factors have causing this, we have seen some, and have assumed others. Most likely we are reading too much into the underlying factors, probably more than SC Stories intended. Obviously all this is done in order for us to have a decent story. The fact that we are here, with our difference of opinions, discussing our views shows the level of our entertainment.
I see Vivian as the main character in this game, and if it gets darker, it will be in relation to her.
Hutch has accepted that she is enjoying the events (even if she does not admit to it), and that there is no point in fighting the situation. And also, why bother fighting for someone who would hurt and betray him like this. She is obviously not putting up any fight for his well being or mental state, especially now that she knows that Hutch knows everything.
I hope this leads to further indifference on his behalf and just not caring at all on what she does. Zero intimacy between them, zero "I love you"s, bare minimum physical contact. From what we have seen, that would make her spiral downwards, leading to her dark despair.