Oh, THAT part has little to do with profession; my spouse's and my jobs were completely different (or so we thought!), but if your relationship works and you are "each other's 'person'", ranting about work is part of the SLA :->
FWIW, my experience:
- Key is to look at sum balance. Yes, absolutely, somebody else unwinding will increase your stress level; but IF unwinding reduces their stress level more than it increases yours (and vice verse when the tables are turned), it's a net win. And it goes beyond work rants; any intimate opening, sharing of concern or anxiety or even admitting past wrongs etc, will impose a burden on the listener. But if you believe or can work it out so that, e.g. "this increased my burden by +10 but reduced your burden by -70, so it's a good thing we did it", it'll help build mutual understanding and trust.
- Show empathy, don't try to solve. Cliche, stereotypical, but a person will tell you when they need active considered advice, as opposed to sympathy and ear. HARD for any of the IT problem solving personalities :)
- As a natural result of first two, you'll figure out who's had a worse day and gets priority; and you'll also figure out how to take some of their burden without becoming overwhelmed with it. Again, if their ask is sympathy not resolution, it's actually a lot less burden upon you than it may feel; or rather, us problem solvers impose burden on us that's not actually there :)
- More personal, but, FWIW... my spouse shared bad stories and rants about their work as a store manager, the drama of customers and supervisors and workers and people and policies etc, for 3 or 4 years. I listened patiently, tried to show support... didn't even realize how much I ingested & learned from it. When I transformed from sysadmin to people manager, after a year I realized that I've been implementing all the hard earned experience, lessons learned, approaches and thoughts she shared. One day, all my work problems were her problems of 3 years ago and it allowed me to succeed in that unforeseen (and somewhat unsought:P) transformation. So as we awkwardly say in my language, you never know what's good for what :)