Do you and your significant other split your money, or do you keep it in the same pool? My husband and I have a system --which works entirely in my favor-- where his money is mine, AND I have a separate account of my own. I'm not sure how I got so lucky. While all major money decisions are made by us together, I'm the primary controller of the cash -- which comes with all the responsibility!
Here's an interesting infographic showing how couples divide their money:
Image courtesy of wineinvestment.org.