I'm still not sold on the "it's all part of their plan" thing. Hutch having a plan I can sort of see (only "sort of" though, because we haven't seen enough of Hutch yet and need that third chapter to balance out chapter 2, as dev said), but I don't see him actively using Vivian/Vivian's body as part of it. If he was to involve Vivian, I would expect it would be more along the lines of "let him think you're playing along, but for God's sake try to avoid any more fucking!"
I also don't think Vivian is going to go home and tell Hutch she belongs to Christian now. Unless we're taking the shortcut to Divorce Town, I just can't see that working out at all - I don't think either Vivian or Christian want Hutch and Vivian to get divorced, and I think Hutch has probably thought hard about it, but if he wanted it, I think he would have acted differently in chapter two than what we did see of him. With little to go by though, that could obviously just be something we haven't seen yet, but the signs are that he still believes the marriage can be saved, or at least that he wants to try to save it.
Obviously not everything that is said is gospel, so Vivian telling Christian that she is his doesn't necessarily mean she is his. She could just be telling him what he wants to hear, but we've had that manipulation-reverse conversation already. She'll probably tell Hutch what he needs to hear as well though, it's just a case of how much truth she gives him and how much she tries to soften the blow. Despite him telling her he doesn't want details, I can see her telling him everything now (you can do that without going into the details of it), but whatever this conversation with Hutch ends up looking like, it's still the one thing I'm most looking forward to seeing.