Proportionate to income can be unfair because if there are big differences in salary, the lower earner will be left with a lot less spending money and if they're the one who's earning less because they're also looking after children, obviously unfair.
OP, who pays the DC costs - clothes, childcare, presents etc? Do these come out of joint income or your spending money? Don't fall into the trap that some mothers seem to do, where the mother's money all goes on the DCs while the father's money all goes on him. DC costs should come out of joint spends.
But the fairest way is for all income to go into one pot and all joint expenses, including pensions, bills, food, travel unless for personal hobbies etc, child expenses, rainy day fund and annual and irregular expenses to come out of that pot, and for the remainder to be split 50/50 to spend as you and your DH like.
If you want to spend all yours, fine. If he wants to save all his, also fine. That's his personal money for him to do what he wants with, not for you to spend.
If the family has spare money and he agrees that you can use joint money for you alone to go to your brother's foreign wedding, fine, but you shouldn't expect it. Have you transferred the balance to a 0% credit card so it's not costing interest?