Yep. A woman I'd started dating took me to a 'swinger' party. More accurately nine or ten horny young Marines, male & female getting naked and engaging in assorted sex acts. Cant remember if any were married, tho most were dating couples of some degree. All probablly under age 25. I was 21 & a couple months, my new gf a few months older. We met for a easy dinner, went to the party which she & some friends organized, had sex with several others, and crashed when the party faded after midnight. I was sold,