Thank you for the well thought out answers. This really hasn't been a concern for us for many years since our secondary partners did not have other sexual relationships.
Incidentally, prior to these partners, one my partners contracted HSV-2 (outbreaks) from someone she was seeing. This was enough to cause quite a bit of stress dealing with how that affected the various people in the various relationships, not to mention not knowing if it got passed on to anyone else, and then having to wait many months for any meaningful testing past an incubation period.

Stressful to say the least.
Thanks again for the replies.
I have done my homework bigtime when it comes to HSV, because a close family member has had it for a very long time (she told me all about it beginning when I was 14) and because other friends, including some in my extended sexual networks, have had it.
The bottom line is that HSV is a tricky little bastard of a virus.
If a person is not symptomatic, then they might not be contagious. Except if they are. Sometimes they are. Especially for a while before and after an "outbreak."
(OK can I just say right here and now that I hate the words, "herpes" and "outbreak." It is my own opinion that they make the condition sound worse than what it is, unless every one of almost a dozen HSV+ people I've known have lied to me about the reality of living with it. I prefer "HSV 1/2" and "symptoms" or "symptomatic." I'll never in my life forget my beloved family member crying when rejected by someone she had become emotionally attached to, for disclosing honestly about her virus. The stigma makes me angry.)
So anyways. A person is maybe contagious, maybe not.
If one catches it, one can go for many years (an unknown length of time) with no symptoms. And if you never have symptoms, then a blood test cannot flag positive. This is because the virus doesn't live in the blood. I forget whether it lives in the skin or nerve or fat cells...but it doesn't float about in the blood. What the test is checking for, isn't the virus, but the antibodies from your immune system trying to fight off symptoms. So no symptoms = no positive test.
And...people who are positive, can test false negative, on account of having not experienced any actual symptoms yet. For possibly years.
I always ask my doctor to do a full panel of all STI tests when I get them done at all, including both kinds of HSV. And I have asked her why HSV is not usually part of the regular panel of tests. She said that there is a high prevalence of both false positives, AND false negatives, and the virus is extremely common and considered to be minor by professionals in her practice. She said, "Yeah, everybody's got it more or less, but if you tell them they don't, then they think they don't need protection. They you have people risking getting and spreading other things. Better to just leave it alone. Also it's more work for the lab, for an unreliable test."
Well then.
Thing is, if you look it up online, just like if you look at say, images of any skin disorder, you're gonna get this horror show of awfulness. But every single person I've ever talked to about this, from the family member when I was young, to a friend in the kink scene who is "out" to everyone (she has it on her fetlife profile)... They report something like a large pimple appearing every several months. One told me it takes his a few days, with Neosporin, to go away. Another told me hers stick around for up to a couple of weeks. One said he hadn't had a symptom in years.
(It is an odd facet of my life, because I'm an oversharer, others feel comfortable telling me all sorts of things about themselves. I get probably more honest disclosure than most people, and I know hundreds of people, so my anecdotal sample sizes are usually higher, I think, than many people might experience...)
Point being, from everything I've ever been told, it's more of a minor skin disease than anything, only really a problem if you give birth really, the worst part about it is the stigma "what people think" which is often false and rather ignorant, and the tests can't really give you a definitive answer.
Oh, and HSV-1? Cold sores? You can so get those on your junk. And plenty of folks have thought they had HSV-2, only to find out it's actually a genital case of HSV-1.
So frankly, in times of my life where I was...shall we say, sluttier... I was simply rolling the dice and hoping I didn't catch anything. I was not under illusions of safety. Some partners were riskier than others, and at least plenty of my numbers were virgins or low risk. The one thing I did was to get tested somewhat often so at least I'd know if I caught something. Protection helps, but even then, it's not absolute.
How do you stay safe? You don't. You take your chances, if you play the game, and manage your risk as best you can, to whatever level you need to, for your own comfort and that of your partners.
But in life, absolute guarantees are pretty hard to come by...