Have a discussion with him.

1.Separate your incomes by separating accounts or whatever. 2.Calculate how much on average you pay monthly : bill, mortgage, groceries anything in common. 3.Devide by 2. 4. Each of you is expected to contribute 50% for common spending if you have same income, and sized to income if not AND has to be responsible for their bills. 5. The rest of your money are for each of you to enjoy, separately or together as you now discuss.

Personally I save and entertain myself with the rest of my money. Inviting my boyfriend to a good restaurant and me paying for the evening include it.

If he wants to gamble with his remaining money, no problem, but he has to understand that he has zero rights to your savings if things go south. So he has to make savings on his own