Events that stand out most in my memory...
The time, at the club, when a guy had my wife bent over a foot rest/ottoman and thrust into her so hard both the ottoman and the wife basically went flying across the room. We promptly decided to relocate to an actual bed... and four or five guys from the audience followed, and eventually joined in.
The time, also at the club, when I was watching my wife in a threesome with two guys and another guy, sitting next to me, said how beautiful she was and how he wished he could have a chance with someone like her. I encouraged him to ask her, once one of her play partners finished, and sure enough he got his wish.
Finally, my first time with the young lady who was my friend-with-benefits for about a year. Seeing a strong, smart, kind of sarcastic young lady suddenly look shy and hesitant as we kissed for the first time... just wow. Given how that whole thing ended, that one's bitter sweet but I don't regret it.