My ex had three separate affairs, over an 8 year period. Before we met she was very promiscuous, but when we met she told me she had been wild but wanted to settle down. Her first affair came 3 years after we were married, she took a college course, slept with her professor (not for grades, they were into each other). It became a regular thing. She told me after 7 months of it. She was apologetic, I was very lenient and forgiving, she promised not to do it again. However, after the first few weeks, the upset feeling left, and I started fantasizing about her with him. I sought out online chat with other men who had the same feelings about their wives cheating, and found out I was a cuckold.
About 8 months later, she started another affair, with a co-worker. It went on for 4 months before I found out. I confronted her, she admitted it. I asked her if she wanted an open relationship, she said no, she'd stop. A year and a half later she started the next relationship...it lasted over a year before she told me, and she said she wanted a divorce, she wanted him more than me. I begged her not to, asked her again to have an open relationship, she didn't want to.
That was over 3 years ago, I still fantasize about her, I'd happily take her back if she wanted, and hopefully she'd be good with an open relationship then, but don't see it happening. Hopefully I'll meet a woman who is into the cuckold lifestyle.