That's not why Vivian doesn't want Hutch to know she went to talk to Christian.
Her reasons are simple and straightforward.
1) The reason is to save her husband's job...
2) Vivian has never met Christian in the six years her husband has been working for him.
It seems obvious to me that she doesn't want Hutch to know... the night before, it was Hutch himself who made it clear to his wife that he didn't know how to avoid being fired.
If you read the dialogues that make Vivian decide to take action, you understand very well that Hutch is incapable of reacting and looking for a way to avoid being fired.
Code:
w "If a new job isn't an option, then you need to keep what you have."
h "What are you talking about?"
w "Well, maybe it's not too late, you know?... to keep your job... "
w "... he hasn't technically fired you so maybe there's still a chance."
h "A chance for what? Mr. Landon getting a brain tumor between now and tomorrow morning?"
w "A chance for you to change his mind. To prove you are still a valuable asset to him."
As you can see, the night before, Hutch is a weak man who cannot find any pathway out or alternative job that would allow him to maintain the standard of living he wanted for his family.
This is not a problem for Vivian
Code:
w "We'll invite him to dinner, cook his favorite dish, drink his favorite wine..."
h "I don't know... I don't think he'll fall for it."
w "It'll work. We just have to get through the day, make him come to dinner."
h "How are we going to do that? He's not a guy to be persuaded or intimidated. Once he makes his mind up... that's it."
h "He'll pull me into his office first thing and cut the cord."
This tells us that he is unable to fight for the good of his family.
So you think he should throw away his 22 years of marriage to Vivian and prevent their son Sawyer from going to college?
Vivian is doing her role perfectly... She is his wife and the mother of their son!
Of course, in a marriage, decisions are made by mutual agreement, which is why it is very important to understand why Hutch married Vivian 22 years ago.
What?
The day Vivian meets Christian without her husband knowing is the first time she has seen him, so she had never cheated on Hutch before.
I don't think your comment makes sense. You are confusing the dynamics of the events that lead to Hutch accepting Vivian's betrayal because she saved him from being fired.