Watching your wife suck other people's dicks is a buzz kill. And she understands that by licking other people's testicles, her husband's boner will get sharper. So these swinger couples swap to sharpen their senses, bring back the novelty, and make their orgasms brighter. Only I would make the lighting not so bright, then there would be more understatement and less embarrassment.
I've seen a lot of things, but I've never seen group sex on stage before. And the most amazing thing about it is that there are no bored faces in the audience! Everybody likes it! Well, direct participants are twice as pleasant: they suck your dick vigorously and the approving attention of the audience. The final chord, bukkake, is so organically blended into the atmosphere of the evening that you cannot help but wonder if it could have ended differently!