This is an area that I struggle in as well. You should approach it because it affects you and the kids when he withdraws money without realizing the needs of your household.
What was his response when you asked about the IKEA purchase? His reaction will give you clue about his state of mind about this issue.
You need to think about what your goals are here.
Is the main concern the $5000 dollars being withdrawn? Is it more that he is spending money in a way that you don't agree with? Is it the fact that he left you stranded with an overdrawn account?
You probably cannot control how he spends or even if he spends, BUT you can tell him that it left you in a lurch and that that isn't OK. If possible, I'd try to include him in the solution, something like, "H, this happened. What should we do?" Then let him come up with a solution.
I'd also try to avoid the temptation to lecture. He's a grown-up and he knows better, but he doesn't need mommy to rub it in that he screwed up.
That's just my two cents, and it's definitely biased by my own situation.
