Ykhjuy

Background:
My wife and I are looking to relocate to another state for family reasons, and we have both been looking for employment in the area we want to move to. Currently, we both work for different companies in different fields, but our respective direct managers are married. This becomes an issue if one of us gets an offer that we decide is worth pursuing, before the other is ready to wrap it up and move as well. Ideally, we would both be able to start at the same time, but that seems highly unlikely at this point.

The question is:
How do we leave one of our jobs without forcing the other to unofficially hand in their two weeks when our bosses are so close?

As of now, it seems to me like there is no way to avoid it and if there is an offer, the best we can do is keep it hush and delay the start dates as long as possible while the other doubles down on the job hunt.

It seems like the issue would only come up if you gave your actual reason for leaving the job (because you plan to move away). Neither of you needs to explain this when you submit your notice. If someone asks for an explanation (which is likely), you can say something else, like

"I need a break or a change of scenery/pace/type of job".

It also isn't necessarily a problem if one boss finds out early. The deal isn't "we'll fire you unless we think you'll work here for the rest of your life", it's "we'll pay you as long as you produce valuable work for us". Knowing that you'll be leaving some time in the next year doesn't mean they'll fire you immediately, it just means that they'll get, at most, another year's work out of you at the job.

From that perspective it might even be better to give each employer a timeline, so that they can allocate projects to people that will be around to work on them. This may or may not work well in one or both of your workplaces, so I'm not necessarily suggesting that you both tell your bosses right away.

The secrecy might be nice in a variety of situations, but it may not be as critical an issue as you are imagining.

As of now, [when] there is an offer, the best we can do is keep it hush and delay the start dates as long as possible while the other doubles down on the job hunt.

You're probably correct.

The only useful thing I have to add to this is that the person receiving the offer should reveal this situation before asking for the extension.

Asking to push your start date without saying why, may lead them to believe that the person receiving the offer is not excited about the offer they just received (maybe s/he is waiting on another offer but will take this one if something else doesn't pan out).

Another thing to think about is that once you use either of your current boss's as your reference the cat is out of the bag.

This is less tricky since you have revealed that both bosses are in your friend group. I expect they would understand and you would worry less about them knowing because they will want what's best for you - you'll have to be the judge of that though.