Three accounts, one shared and seperate accounts each. Either that or divvy the bills, maybe one person pays the rent/mortgage, the other takes the other essential bills. No real secrets, but unless things are a bit tight or you’ve a big saving target you need a bit of freedom to splodge a bit of your hard-earned now and again. Couldn’t (hypothetically) get to the point where small-to-medium expenses were being questioned, etc. I’m pretty fucking single, though, tbh.