From reading some comments I'm surprised joint account doesn't just mean money for rent/mortgage, bills, groceries, repairs, house stuff. Share the money that's meant to be shared and don't share the money that isn't. I don't want to spend my partner's money on things that exclusively will be used by me, it just doesn't make sense.
in marriage all money is to be shared. you can give yourselves an allowance, but the money you earn is just as much your partners, as the money your partner earns is yours.
