Mine was with my first serious girlfriend of 1.5 years. We were kind of on a break (not really, she only said it to make me show my emotions and say I wanted to still be with her) and I decided to use it as an opportunity to fool around a little since I knew the relationship was serious and wanted to get some more hook ups in if I was going to be with this girl forever once the break was over.
So my friend wanted to visit this college that he was interested in going to the next year, and coincidentally my ex's best friend went there. I was good friends with her too, so it was no big deal for her to show me and my friend around while we were there. My friend expected me to make the arrangements, but I was busy with work and didn't feel like exerting any energy on that since I was already driving the 7 hours up there and it was really his trip. I told him if worst came to worst we could just find some girls at a party and go back to their place. He didn't have much confidence in this but at the time I was smoking a lot of weed and would come up with these ideas that would have their way of working out probably since the weed made me so calm, yet confident, and people seemed to like that in me.
Anyway, we get up there and call the girl I knew and met up with her at a party. She was with her new best friend, and after a bit of partying and bringing up we had no place to stay the girls new bestie said that her roommate was gone for the weekend so we could stay in her room for the night. We all hopped in my car (I was mostly just smoking weed so wasn't drunk) and stopped at my girlfriends friends room really quick so she could get her pillow or whatever, then we proceeded to her besties dorm. The bestie told me I didn't have to sleep on the floor, and that it was no big deal if I wanted to sleep in bed with her. It took me about 2 seconds to make up my mind on that one (hmmm, sleep on a cold, dirty floor, or share the bed with a drunk blonde sorority girl?)...
Next thing you know I'm spooning with this girl and she takes my hand and puts it down her pants. I wanted to just hook up a bit since the girl I knew was in the room, but this girl wanted to bang. So I'm trying to come up with excuses, said I didn't have a rubber but she magically produced one, and since it was cold out and I had no place else to go I kinda had to do the dirty to stay there (gotta have manners after all
). I tried to stop but then she was yelling at me, so I continued until she let me stop.
The next morning my friend was like what were you getting raped or something, I just heard you saying "I can't do this, I wanna stop" and the girl yelling at me to continue. Anyway, after an awkward morning we finally left, and after driving for 30 minutes I got a phone call from my girlfriends friend, saying her friend said she had something to tell her, and if I wanted to come clean about anything. Now my friend said there was no way she didn't hear us, but she was playing dumb or something. So I played dumb and said no and hung up, but then she called me back 20 mins later screaming at me for having sex with her college best friend when I was dating her best friend from high school (she was in college now too, I'm no pedo). Then she told me that we had to tell my ex about it. I pleaded with her that she was under a lot of stress and there was no need for her to know, and that we were on a break so it didn't count (anyone else who has done this will tell you that line doesn't work) but she insisted, saying "either you tell her or I will." So I said "ok, have fun telling her, but I really wish you wouldn't."
30 minutes later came the dreaded phone call from my now official ex. She was crying hysterically, asking how I could do this to her. It sucked because here she thought I was all proud of this and like I went after this girl to bang, when in reality I was just trying to make out with the girl, and was basically forced into the sex. I felt pretty terrible about it, but lesson learned. So yea, that was more of the official breakup on the phone there, only an hour into my 7 hour journey home, so only 6 more hours to sulk in the sleazy misery that I brought upon myself. I really loved the girl and later realized that at the time my GAD and fear of death was causing me to push away those I loved, since I thought I would be saving them from grieving over my death that I felt was sure to come within a year of that time [read: me getting prescribed benzos and SSRIs a short time later].
About 5 years later I saw the girl I banged. I was on the train headed to the bar, and right before getting off we spotted each other. I saw her give me the "were you the guy I had a drunken one night stand with 5 years ago in college (which was 7 hours away from where we were at that time making it even crazier)?" look, and I just nodded my head at her really quick, then hopped off the train, disappearing into the night.
Half way though my post I was thinking this was a "have you ever cheated?" thread, so this applies to both that thread and this one.