My husband left his job to enter FIRE before me, though I brought the formal FIRE concept into our marriage. We had, however, both lived according to what are now known as MMM principles for most of our adult lives, so FIRE was logical. But, living as if FIRE were in our future and actually making the leap when the time came were two very different things.
Paying off our home (surprise!) made it very difficult for us to continue working as we had been. There was, quite literally, no reason or any urgency for paid work anymore. Suddenly, the FIRE leap came a lot more easily, but still freaked us out a bit. So. The plan was my husband would FIRE first (he being the more miserable in his job of the two of us, with the super soul-killing commute) and I would follow in a year, maintaining health insurance for both of us in the meantime.
Well, that lasted one whole month. Newly FIRE husband wanted to do things like take road trips I wouldn't be able to go on with my limited vacation time, and do other fun things like play frisbee at the beach and hike. We completely work as a household and had a shared plan, and I was STILL envious of him. Envious enough to join him in FIRE ahead of schedule. We have no regrets about ANY of it. If anything were to happen to him, as it eventually will to one of us, we will be so, so happy to have had this incredible time together.
I am not a person to judge anyone's marriage or give unsolicited advice but, in general, adopting the concept of a household has been a transformative one for me, not just in regard to marriage but in regard to our entire lives. Wendell Berry has written beautifully on this subject, to name just one, and the Allan Savory concept of holistic management (which is for land, grazing, and soil health) applies very cleanly to life in general.
Changing my cognitive frame to "household" from "job/worker" was so necessary and helpful to FIRE. Until the possibility of FIRE was REALLY real, even I did not realize the extent to which I had been brainwashed by an industrial, job-centric mindset, i.e. "Work comes first, choices are always made around a job and not a life, work is something that happens totally apart from the home," etc. It's also a very individualistic way of being: We choose the best jobs for ourselves, usually, not others; work happens totally apart from our families; life is segregated into spheres; etc. If you think about household, and holistic household health FIRST, a lot of other things also change.