I have seen a female friend naked on a trip together as I had to share the room with her and thought I was asleep when changing the clothes. She learned that I saw her and we joked about it but no sex.
Before we actually end up being a cuckold couple. Wife and I got bit druuunk (we were married for only 10 months) and was in bachelor mix bachelorette party of my cousin brother. I got too druuunked so my cousin bro had to drop me to our hotel room where I apparently (too druuunkd) confessed my cuck feelings to my wife infront of my cousin bro and 30-40 minutes of conversations, tease and encouraging wife for a moment she lost control too and we three end up being naked together in the bed. He kissed my wife but immediately got interrupted as his fiancé called him asking where is he missing for so long and it didn't lead to sex. He had good 3-4 minutes of naked admire, touch and kiss with my wife but no sex.