DP and I have known each other for 7 years, been dating for 5, no kids, probably not ever having any. We used to work for the same company, I got promoted, moved to a different department, and eventually DP quit right about the start of lockdown because he felt like his career was 'going nowhere'.
He became a self-employed day trader, started trading options, made a bit, but ended up losing far more as he kept opening new trades saying that he's going to make back all his money. Since then he has moved to crypto in addition to options. Same thing, he made a bit at the start, pumped more money into various currencies, and is now trying to make back all the money he'd lost again. It's not traditional gambling but the way he goes about it seems like gambling to me.
Recently he's stopped putting money into the joint household account we use for bills, groceries etc shared stuff (he claims all his money is 'tied up in investments') and in fact has used the joint account to pay for things like his bloody glasses and other personal stuff. Confronted him about it and he claims I'm controlling and that the money should all be shared anyway as we'd be married someday and that if he 'makes it big' (I'm trying to be supportive but I have serious doubts) it'd be my money too... How would you go about dealing with the finances if your partner 'gambles'?