Believe me after 22 years of marriage it doenst matter is the wife is unhappy with her sexlife and it doesnt matter how much she enjoys sex with Christian that holding hands in that way is beyond from being loyal and is again any deals . it is too intim. Like two lovers. This is very danger sign and if Vivian is naive to recognize that kind of detail it means she is very very dumb and not that clever as she looks like.
At this stage Christian has become more of a priority in her life than her husband. We can all see it, and I'm sure she knows it too.
Vivian is naive if she thinks she can maintain her marriage after this. Regardless of an open marriage the fact that you can jump into it so easy and freely do it in front of your husband shows she doesn't care or she is just enjoying it for as long as she can with the delusion everything will be ok.
This is why I previously mentioned that that last scene in their home didn't make sense and came out to unrealistic. She was making the decisions to that point, and out of all the times in the world she decides that Hutch "opening" the relationship is where she will now let him take charge She knows how much this is going to hurt and humiliate him, but thinks it is for his own good? Come on that whole scene did not fit in with the quality of the rest of the story.
One other thing about open relationships. The require complete trust and transparency between partners to work properly. Hutch and his wife do not have that at all. If they cant be honest about what has happened so far, going forward is only going to be a disaster (for Hutch especially and for Vivian as well).
Vivian doesn't love Christian.. She loved his big and hard cock.. vivian can't give up the pleasure she gets from it..
Just once i would love see the betrayed husband not be a total loser in the genitals/sex department, with every other guy being well hung sex machines. Technically we have not seen what Hutch is packing, but from the story we can deduce it is not as big as Christians. Hopefully we will see him in action, and fingers crossed, he is packing an above normal member (just not as girthy). Also hoping he has the experience to please a woman when he wants to.
Looking forward to the next chapter, i know what direction I would like it to go, but I see it going in another. Hopefully it stays original and does not full too deeply into the common NTR tropes.
I'm also hoping the whole story would be complete in 4 parts, and not 9.
like you said "to each their own" but happy travels on finding the right story and game for ya!!! 
