I had a wonderful open and loving relationship for the 25 years I was married to my first wife. We had many experiences that were erotic sexual encounters, both together and alone. We always knew what the other one was doing and had no secrets.
There were many memorable moments that I look back on that are still stimulating. But the first one is still the one that stands out most vividly. We were overseas (I was in the military) and my wife was young, relatively inexperienced and curious.
We had been married almost a year and a half and our first son was 6 months old and we had just moved into on post housing, after living off base for about 9 months. We had a group of 10 to 12 single (or at least unaccompanied) guys who would hang out at our house as a break from barracks life. They could relax, play cards, watch TV and get a home cooked meal.
My wife was particularly attracted to one guy, named Ron, who was very good looking, due to an Italian Mother and a Polish Father. He was tanned and fit with dark hair and green eyes. She would share her fantasy about going to bed with him and wondered what it would be like. This would get her hot and wet as I played along describing the things he would do and say as I carried them out in bed.
This was a topic of conversation ever since we had been married, but it stayed in the realm of titillating fantasy. I hinted that she should find out for herself since it was OK with me if she did. I didn't tell her my fantasy was to share her with other guys or loan her out, since I didn't want to pressure her in any way to act out her fantasy just because I wanted her to.