As a couple it is really easy to want to search for equality when it comes to who gets what. Have you ever heard someone in a couple say, "Well, he got a new drill, so I am going to get a pedicure."
This scenario could play out indefinitely. You could get yourselves into a real pickle if you are searching for equality with your spouse in who gets how much money to spend on themselves.
Now you should budget blow money for each of you and that will help, but there are still going to be times when one of you gets something outside of that blow money. Even if it is just a throw pillow (I love throw pillows) or something. Typically a dude isn't too interested in that and may see it as the wife got something she wanted so now he wants something too.
Now if one of you is seriously being denied any chance to use blow money or whatever then that is not cool (professional term). But if you are in a healthy relationship and find yourself justifying a purchase you are about to make with something like, "He/She just got X so I can get Y.", stop yourself. Put it back and exit the building. It is such a bad habit to start and could be a costly one.
Instead try finding joy in your spouse's joy. Be happy for them when they get a special treat. Whatever you do, don't keep score (outside of necessary budgeting of course!).