We have fantasised and played with the idea as a couple for many years.
After going to a sex shop and treating my wife to some sexy lingerie, we started talking about a swingers club we had looked up a few times nearby. My wife then whispered in my ear "So you going to take me there or not." I obviously jumped at the chance as I never thought she actually would. We did a little more shopping and she tried on a few more short teasing dresses and even started to tease me by calling me over to the changing room and coming out in nothing but a short dress, which she duly lifted and revealed she wasn't wearing any underwear and had a little play with herself. She was always daring when in the mood.
So we popped back home, got showered and took our time choosing something teasing and daring for my wife to wear. Short easy to remove dress with suspenders and panties over the outside so they were easy to remove.
As we approached the club, I was convinced my wife would change her mind, (we had never done anything like this before, although fantasised about it for years). However, she simply leaned across and said you will look after me won't you and kissed me intensely. Of course I would I replied. I love you.
So in we went. We were warmly greeted at the door and was shown around the club, with all its different rooms and a general reassuring chat about how to behave and how no one should pressure us etc, etc.