That would, on the surface, seem to be a kind and reasonable approach. If you pop positive, stop playing to save others the same fate. But, after further review, is it really reasonable?
At any given party of say 200 people, unless an argument can be made that swingers as a whole don't have the same statistics of the general population, there will be somewhere from 40-50 people who have HSV-2. (And, of course, that particular statistic could be quite low if my original hypothesis is correct.) Of those 40-50, 36-45 of them have no idea they're infected, so out of 200 people only 4-5 of them have HSV-2 and know it. Even if every person who knows they're infected decides not to participate it only reduces the actual number of HSV-2 participants by a handful.
So, on the one hand, it's the ethical, reasonable, and kind thing if you know you have HSV-2 to not participate, or at least participate only after full disclosure. On the other hand, one only needs to go through a relatively small handful of playmates before one has a virtual certainty of having played with someone HSV-2 positive, whether they know it or not. Frankly the expectation that it won't happen to you is, statistically speaking anyway, unreasonable.
I'm beginning to think an HSV-2 infection is inevitable if you participate in the Lifestyle long enough, unless either the stats are wrong, or an HSV-1 infection (which virtually all of us have) offers statistically meaningful protection.