The first time my wife cucked me was when we were in college. We were at different schools, hours apart, but still serious. Without our own cars, it was difficult getting together. One weekend I was able to borrow a friend's car and went to visit her. We had sex, then after we were done, we were talking and she said it was hard being apart. We were young, in shape, and had libidos I can only dream of now at my age. Early twenties are a great time; no responsibilities other than school and going out to have a good time. I knew she was hot, she knew she was hot, and her social life was always full. Over the past year, I knew there was no way she was not getting hit on constantly, and knew, deep down, that our distance was leaving her unfulfilled. She was always the dominant one sexually.
Let me give you an example- the story of how we started out. She initiated our relationship one drunk night. I had just met her earlier that day, and we hit it off amongst a group, then met up later that night at a party. After a bit of drinking, she grabbed me and led me out back in the yard where we had lots of privacy. She basically attacked me and put her hands down my pants to get me hard. Within minutes she had me hard and got my cock out. She demanded, "fuck me NOW!" She was like a dog in heat, she had to have cock. I didn't last long and came in her quite quickly, a bit embarrassed it was so fast, so I knew she didn't cum. She grabbed my hand and made me finger her to climax. Finally, she calmed down and we kissed a bit before returning to the party and friends.
We exchanged numbers and started talking a lot and we traveled to meet each other as much as we could. Eventually we had a real relationship and dated for a over a year, falling in love.
Back to the present day conversation. We both had been feeling the absence. I know I was jacking off daily, trying to keep control. I knew she was a very sexual being, I've known from the beginning. We talked about our frustrations and the ways we tried to handle it (porn, masturbating, phone sex, etc.). After some discussion and emotional sharing, she let me know she had a one night stand with some guy she met at a bar. She promised me it was just sex and that she loved me as much, and more, as before. She was drunk and let her natural sexual needs take over. I was pissed at first, but slowly got over it and the fear/anger turned to horniness. I asked her if the guy made her cum, and she said "many times!". She told me about how he was dominant and forceful, which I certainly was not. He fucked her hard, and apparently in multiple positions throughout the night. She told me that he got her to bend over and fucked her doggy while he played with her asshole. Normally that is off limits to me, and our sex was pretty vanilla missionary. She said he then flipped her over into that position and that she loved how he was dominating and directing her. Over the course of the night, he fucked her multiple times, am without a condom. She said the next morning she was still leaking cum and finding it dried all over her body.