My wife came from a blue-collar family. Even though mom was a nurse and dad was a factory worker for the great yellow father, they would often run out of money before they ran out of week.
My family wasn't like that. Those of us who were tradesmen always had an eye toward hanging out our own shingle - nobody wanted to be a wageman. I thought I did, but as I got further down the road the more I got really restless. Those of you who really know me - can you even imagine me working for somebody else? Yeah, me neither, but I did. For 10 years I did.
When I took the plunge in 1997, Mrs. Galat had one request: "just give me a check every month. Please don't talk business with me - I know I can't handle it". She wanted the same amount, enough to cover household expenses, and a bit left for her to dispose of as she would.
In the beginning, there was no extra for "Stan's fun project"s - but by 2000, there was a pretty healthy surplus after all of the obligations (including an aggressively funded 401K, health insurance, college savings, etc.). I asked if I might have a fun car, and Jeanie said, "Sure. Anything but a Corvette. Don't be that guy". I was crestfallen, because what I wanted was a C2 'vette.
As fate would have it, I saw a Vintage Speedster on the cover of Kit Car magazine, and was bitten by the bug. They were just a VW Beetle, under the skin. How expensive could they be, anyhow?
Fast forward 10 years or so, and I'm on my third car and am building my second engine for the third one. I found out exactly how expensive they could be, anyhow.
Jeanie never asked, and I never told. I made sure there was the agreed upon (adjusted) amount in her account every month, and she was happy. Though thick, thin, fat, lean, broken, strong - that check is always there, and she's never complained about the car. Even when I built an entire house around a lift for it, she was OK- as long as the check was there.
She's my closest confidant now, and I discuss business with her all the time - but she's still very, very hands off... and so am I. The trick is in not crawling around in her books, and she's OK not crawling around in mine. I care not if she spent $500 on high-end artist's paint brushes, and she's not asking how much it costs to ship twin-plug heads to Denmark.
FWIW, all of this stuff pales in comparison to what it costs to build stuff (garages, houses, etc.) anyhow, and the return on investment is way better.
Separate accounts. It's been a really good thing in our marriage.