We have a budget and use YNAB app for our house hold budget. We both get a monthly spending allowance as part of the budget. All expenses are entered into the budget system. When we discussed the doing our budget using this system I thought it was a great way to manage our expenses and spending. Having said that one item I wanted was for each of us to have a monthly spending allowance the amount we be both agreed upon. This allowance is for both of us to buy the things or enjoy the experieces we want as individuals. If I want a facial or want to save my allowance for a number of months to buy a bag I can using my allowance. It has been the best way for us to avoid what you are dealing with. I don't ask him what he spends his allowance on and he doesn't ask me. He knows handbags are something I save for and buy with my allowance. It works really well I never have to justify what I am buying he knows it comes out of my allowance money. I personally highly recommend both of you having some system like this. It has been the perfect solution for us.
We do exactly this in my house both for my luxury and beauty items. As long as I don’t go over that amount, it’s business what I buy. While my husband wouldn’t dream of spending what I do on some items he understands that it makes me happy and it’s within the agreed upon amount and budget overall.