If you have to ask the question then I think you know the answer.
My wife and I have personal budgets (lord, that sounds w*nky) specifically to avoid such questions. There are 2 rules of operation;
- we can buy whatever we like below a certain value without asking the other half. We agreed on this because my wife felt guilty about buying new jeans and it just felt silly to me that she should feel obliged to ask my 'permission'.
- we have a total personal annual spend allowance. This was decided to limit me! I can fritter that away as I like on 'rule 1' purchases OR spend it in one hit. My call but once it's gone then that's it, no budget over runs!
I have to say, for all it's spreadsheet-ness, it does work. We no longer have to ask questions, or feel selfish, about personal spending. And I'm no longer spending the sums I used to on N+1 cycling stuff.