I wasn’t at their wedding, but many years ago, I dated this girl and we slept together a couple of times. I met her through mutual friends, and when we called it off it was amicable and we still saw each other at the occasional party or social event.
She got a new boyfriend who she went on to marry and have kids with, and he came along to the same events so I talked a bit with him knowing every intimate detail about his future wife
Never knew if he was aware of our past relationship or not, and I don’t see that group of friends much anymore.