In her previous marriage, my wife's husband agreed to get married only if the relationship COULD be an open one. My wife, who was 24 at the time, was the first to take advantage, mostly because he wasn't attentive, and busy and being younger, she was craving more. Her divorced brother in law lived down the street and she aided his transportation problem by driving him to work. They were attracted to each other and started to get physical, and she was excited to be "hands on" him when they were in the parking lot of his night time employment. Only once did they have the closest of encounters, and she thought things were too close to home so intercourse was limited to once. She did continue to appease his appetite in the parking lot with her strokes as replacement for penetration. Within the month she and her husband rented a different apartment, and the encounter ended and neither spoke of to to her husband. They stayed married for five years. I cannot speak for her reasons or feeling, but I will say that libido is a very hard thing to control and managing the situations might be tricky.