A little different twist to the stories... my wife had a brides maid that I had fucked and always thought was incredibly hot (unfortunately not all too well balanced). Anyway, one night of "hanging out" at my apartment and drinking, I was flirting with both my fiance and this really sexy girl. blah, blah, blah, We ended up in my bed. My (now) wife watching her suck me and eventually fucking her. So there wasn't a big secret to hide while at my wedding. (I love our wedding photos)
However, when she married a friend of mine some years later, all three of us had a sexy secret and I loved her in that wedding dress.
It's ended up hurting no one as we are all still friends and have been true after marriage (all parties involved).