Sex Letter I Read In Todays Paper

My wife and i were over at a friends house. It was just him and his girlfriend, and we all got really, really drunk. To cut a long story short we decided on doing a wife style swap (which we had joked about before), and everyone was up for it. My wife went into the bedroom with him, and i stayed in the living area with his woman. It wasn't long before i could hear my wife having sex with him from the room. I kissed and fondled with his girlfriend, but we never had sex. Infact it wasn't too long before we were both asleep, which was due to the all the drinking. The next morning i just woke up, and i could her my wife going to the bathroom. I assumed she would come straight in to meet with me after it, but she left the bathroom, and went straight back to the bedroom and had sex with him again. I couldn't believe it. It was different at night when we were all drunk and had basically (stupidly agreed to it), but in the morning after ?? Once i spoke to her, she said to get over it, and we were all to blame for it. But how can i forget it, she went back for more the next morning. I wish this all never happened.