We both work so it really is "our money". It started when we got our first house. We wanted an entertainment center but didn't see anything we like in the price range we wanted to spend. At the time I was running a race car team (running, not owning), no wood working experience. She said, "Why don't you just build one"? I said I have no idea how to do that. She said, that never stopped you before. So I bought a tablesaw and a router, and off I went. Still using it to this day. Woodworking turned into a great stress reliever and I've built a lot of stuff for the house.
Along the way cars stopped getting parked in the 2 car garage. More and more tools got accumulated. Projects got a good bit more diversified. Bandsaw, wood lathe, etc. Every time I got a new tool I made her something with it. Then she knew what it could do. I did stuff for neighbors and friends. Always stuff that was no big deal. Her projects were always space shuttle material but that was fine.
I don't remember what came first, the need for or the want of, a metal lathe. I looked for a decent used one for over a year. One Saturday morning I was looking at Craigslist over coffee, and complaining how much people were asking for a piece of ****. She came over, put her hands on my shoulder, leaned over and whispered," Why don't you just quit f**king around and buy the new one you really want. Funny thing is, with the wait, it actually did show up 2 days before Christmas

Of course after I got it, she said what does that do? I said it makes round things out of metal. She said, Oh okay, with a blank look on her face. So I made her something, don't remember what. Then of course you have to have a mill to go with the lathe. Same question from her, same thing from me.
I finally figured it out. I get tools, she gets stuff made that she wants. Works for me.