Before I saw this second post about the gambling, I was going to suggest a joint account which you both pay into which covers things like meals out together.
But if he is a gambler (is, not was - all addictions are life-long even when not actively being pursued), then NEVER have a joint account.
You need to know what his wages/salary is, what the mortgage is, what the regular bills are that he pays, and do the maths to see what he has left for spending. And you need access to the mortgage account and all the other bill accounts to check that it has all been paid every month.
Then you need to add up everything you spend on the household and DC, to check whether your 'spending' money is roughly equal to his (or perhaps you both get spends proportional to income if not equal). If the situation is not fair, he needs to pick up another cost to even it out.
Then you need to check all this again every three months or so, and keep an eye on your own credit record.
That is if you don't just split up and separate your lives and finances.
To sort out the immediate problem, tell him you will be asking for a split bill when you next go for a meal. If he objects, then he can pay for the lot.