My soon-to-be ex is the same way and that was the main cause of our breakup. He had no idea of how to handle money or budget money or anything else.
If I tried talking to him about ways to pay off our debt, he would scoff at it.
If I tried talking about budgeting out a certain amount per month for each expense, he would scoff at it.
He overdrafted our checking account by taking money out without telling me and payments would bounce, costing us $35 per bounce. I would tell him. His response? "It's my money, too".
I would make a $50 payment on a credit card; the next day, he would use $40 of it.
He would run to the ATM almost daily to take out cash advances from his credit card. I would try to explain to him that he's being charged $5 for the ATM fee, $5 for the cash advance, plus a higher APR because he's taking cash rather than using the card for a purchase. That $20 would end up being $35. He scoffed at that as well.
We could NEVER break even, no less get ahead. I would tell him that we HAVE to be more responsible with money so we could save in case of an emergency ---- scoff, scoff, scoff.
It caused sooooo much stress on me and really did a number on my health.
After a while, I just got disgusted and our marriage was OVER. I couldn't even stand looking at him. This was back in 2002 and I'm just now getting around to filing the divorce papers, etc. We've (very unfortunately) been living together this entire time because (financially) I wouldn't have been able to make it on my own (because of all the debt). Now? I have a plan. MY debt is almost paid off (his is a disaster and thankfully we have no joint accounts!) and I am saving money to get out of here with my daughter. Once I'm working full time again, I will be squirreling money away and, by this time next year, my daughter and I will have our own place.