Assuming that it wouldn’t happen is maybe your mistake. It is a constant process the rest of your life. I just silently move my wife’s stuff out of my space and put it in her area where it will visually bother her and then magically she finds a better spot for it or gets rid of stuff. Renting storage space is an option, just understand that like a shelf, it is a self fulfilling prophecy and it will become your job to move stuff back and forth😎