I slept with my best friends girlfriend while he was away

So 6 years ago I was fresh out of high school and I was around 18 years old. I had always been fairly close to this one friend of mine ever since we were kids. I dont wanna say his name for obvious reasons, we will call him John. Well John and I would always chill, and one day he got this girlfriend he met at school, we will call her Kate in this. <br><br>Now, at the time I didnt really like Kate all that much because she came off as a bit of a snob and seemed to be a bit too good for John. Well John would spend most of his time around her after he got her and he didnt have as much time to chill with me anymore. I didnt really mind, but I thought she was using him for money and I would often tell him. Well, one night me and John decided yo chill and have some good times. We decided to hit the club together and we were both drinking heavily at the time. I remember the night vividly because John was being a fucking idiot and making a scene and acting all sorts of dumb. So we left the bar and I was driving us home. When we got to his house he was so drunk. He passes out immediately in bed and during the night I just sleep on the couch. <br><br>In the morning, I wake up to a knock at the door. It is Kate. She is in pajamas, which seemed a bit weird because why would she come over to Johns house in fucking PJ's and she didnt even know that I was there. Anyways, she walks in the house and John is still sleeping in bed. She sees me and is shocked, but not nearly as shocked as I was at the sight of her. She tells me she will wait for John to wake up in the living room. So I am just fucking around in the kitchen, and I hear this noise coming from the living room. I look and see that Kate is fucking masturbating. I was in shock, and the only thing I said was what the fuck do you think you are doing. Next thing I know she comes into the kitchen I am in and she is buck ass naked. I was in fucking shock. I dont know what came over me, but for some reason I was turned on and I ended up fucking her in the kitchen. <br><br>While we were fucking she was calling me John the whole time, I didnt really have time to think about it and I just assumed she was calling him that because she was boyfriend and girlfriend and thats what people do when they are fucking sometimes. I finished and then around 2 hours later John wakes up and is pissed that Kate is there. She made up this lie of how I tried to hit on her and how she beat me up. I went along with it, and that was the last time I saw Kate. <br><br>Around 6 months later I get a call from John saying his girlfriend was cheating on him. He said he is sorry for being a dick to me and that he knows it wasnt my fault. He told me that he broke up with Kate and he is moving away. He told me that he was going to miss me and all that bullshit and I realized that this dude is my real homie. He was the most genuine dude I have ever met, and I was fucking him over by fucking his girl. Im still friends with him too and it kills me to this day to know how much of a piece of shit I am. I feel like such a fucking low life, and I can feel the guilt eating away at me.