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.
What a charming Asian girl. I really liked the moment when she put a condom on him and then took off her panties. At that moment there was such a trusting atmosphere that I wished I was in this lover's shoes myself.