I am having an issue that I am not sure I need to discuss with my SO or just let it slide.
OK--I admit I am a control freak about some things...and finances/money is one. I pride myself in having decent credit and some restraints when it comes to spending and saving.

a few months ago my SO's ex father in law (that he still calls dad and that is cool with me) asked to talk to me privately at a family function (that BM was not at because she doesn't talk to her family other than her mom) Ex FIL told me that my SO was pretty crappy with money management and that he hoped I was better than him at it because his daughter was bad so neither of them during their marriage could save a penny. (Which I understand....we all need to teach our children how to manage money because most of us (even myself) can be horrible at it at times)

Anyway--back to the convo with Ex FIL. We talked and he said he set aside money for the grandkids (my skids) and he has money set aside for his ex SIL which he calls his son still. BUT the money is for later or when he passes. and he just wanted to make sure I would be able to manage. So, I said I was pretty good and had savings of my own and thanks for the concern..

(I am not working full time currently and my SO does not mind, does not complain, I take care of the house and skids when needed and he does not think of his money as just his it is ours.)

I talked to my SO about the conversation because I have nothing to hide and it was general concern from his ex FIL. So we planned on doing finances/bills together every month and that was dandy.

In reality I monitor and pay the bills and he has no clue what I pay and just takes money out all the time without checking with me to see if we HAVE any extra funds available. After I had to get money out of my savings to cover a payment because of him twice I started getting on him about this and he got upset about it. I do not want to be a nag but SOMEONE has to be responsible..and Thank God I have my own account still!

Every paycheck he puts in all into our joint account but $150 or so cash he has for spending money/gas/lunches whatever. I have no issues with that. BUT The past 3 months he has been taking out $300-$400 and it is no where to be found (I know his hiding spots) He also has lost money (or I found it laying around and never told him waiting for him to say something) and he has never said "Did you see a $50 bill laying around? EVER. I have found $230 total on the floor and picked it up and he has never mentioned it to me.

So--long story short.. should I bring up about the money he loses and never mentions to me? because what if he really loses it elsewhere or the kids are stealing it (instead of me picking it up and putting it back in the bank or toward a bill)How much more could we be losing? AND should I be asking him why he is taking out more each month? I do not want any secrets with him and I know he wants to buy me an engagement ring but be a surprise later this year or next so I do not want to stir the pot and be a money Nazi but...what should I do?