While I have no moral issues with it, there's just too many potential fun diseases to exchange nowadays...
Condoms!
@Lia65 Not to be a killjoy - but condoms are limited to cocks, and what cocks can do. They don't encase tongues, and anuses, or prevent all the other lovely potential combinations of parts - especially if more than two are playing simulraneously. And regarding swinging specifically - there's no possible way to know who was with whom, before you mingle with someone. Folks can have been exposed to things without even knowing themselves, until, or unless there are obvious signs.
Reality.
@evergreen while I'm pretty new to the lifestyle, I have found that everyone I've met and decided to have sex with are experienced in the lifestyle and are very careful and always play safe. Is it 100%? No. But neither is dating or even marriage. I get tested every 3 months and I know many others who do the same. Probably a higher percentage than the"normal" population. The reality is... That it's possible to be safe. Swinging isn't always anonymous. There are actual friendships and regular partners also.
What Lifestyle? I have a healthy lifestyle.