She asked me, for the first time in 5 years, to see my actual paycheck. I told her since we are essentially separated, that I was not comfortable showing her.
Was this a good or bad decision?
Why don't you want to show her? Are you trying to punish her for her choices, are you trying to protect yourself in the event that she divorces you? Are you trying to hide extra money away without her knowing?
I can't comment on whether or not it was a bad decision without knowing why you made it.
Here's the general rule however -- your wife resents the hell out of you right now. She let things build up without airing them for a long time, so there is a big load of resentment.
Each interaction you have can either add or help to remove resentment. If you blame her, shame her, make her feel badly because you are sad, etc. etc. it's going to make her resent you more.
If your goal is to reconcile, then you should have a "resentment yardstick" and measure your decisions against it -- will this make her resent me more or less?
I would say that hiding your payslip will make her resent you more, not less. If she sues you for divorce, it will be a discovery document and you'll probably have to hand it over anyway with the rest of your financial records so I don't know what you're accomplishing.
On the other side of your resentment yardstick you have to have your boundaries. You cannot and should not be a doormat in the interest of reducing resentment. This is a difficult balance, however, because your boundaries really have to be about protecting you, not punishing her.
What are the appropriate boundaries for the LBS to have? That's a very personal question and only you can answer it. One example might be that if W was spending the money from your joint account to buy gifts for OM, you would establish a boundary that if she continues to do that, you will start paying the bills and buying the groceries out of your own account and stop funding the joint one.
You're not telling her she can't buy gifts for OM, you're just saying she can't do it with your money.
That's a pretty extreme hypothetical, but you get the idea. If what she does or says is going to hurt you, then you establish a boundary that you will not accept that treatment, and to prevent it, you will take these actions for yourself. You can never tell her what she can or cannot do, only what you will do.
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015