Common Law requires an x amount of time, right? You could make it serial- three years with this one, one year with the next, etc. Or you could agree with your partner that the night before Common Law kicks in, you kick her or him out. You could always get back together the next month or so.

Speaking of ploding- there's an old joke that goes:

A man had been down in the mouth all day and finally burst into tears. Aghast, his friends asked him what was the matter.

He sobbed, Twenty years ago I thought seriously about killing my wife. And I can't get it out of my mind that I would have gotten out of prison today.