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.
The main thing for girls is to feel that they are valued, to hear the words that are pleasant to their heart and not to rush. She will still say Yes, only it will be her choice. So the stranger acted completely professionally - for that he got the award. And she's a great nipple.
Ooh, super...