Cheating on your girlfriend by design

[SpyStrip]

Has anyone planned and executed a "cheating on your girlfriend" event purposefully?

I did this once, and wonder if anyone else has done something similar.

This was years ago, before I was married and when I was going steady with a girlfriend.

She told me one of her girlfriends who I knew and had met a few times was going on her third date with a guy she was unsure about, but that she was probably going to go to bed with the guy at the end of the date. My girl and I laughed about this and we left it at that.

The next day, the day of the date, I showed up at this girl apartment and gave her the excuse that I was planning a surprise birthday party for my gf, and would she help me with this. It was true, but the reason for my visiting her was more underhanded on my part. After we discussed the surprise party, I told her that Lisa had told me that she was going out tonight with the guy she had been dating, and teased her about the possible outcome of the date and she laughed about it. From this point on, what I did was all by design. I asked her if she was going to wear something especially nice for her underwear, and she reacted as though I had caused her to give up a deep, dark secret. She admitted she was wearing something that matched, and that was really good looking. I asked her if she would let me see her in it, and moved closer to her and somewhere between being playful and being wrongful, I looked at her to let her know I was checking her out. She made a shocked reaction, but then one showing her excitement. I asked her if she enjoyed undressing for a guy, and played with the straps of her tank top. There was about five seconds of silence, and then we began undressing one another. We began making out and were on her bed a minute later. We went through about 5 positions and she told me I could cum inside of her and it was fantastic. I told her afterward that being inside of her was wonderful. I even said some intimacies about it and she loved it. Afterward we showered together and we both said what we did made the upcoming evening more exciting because of what we shared. It had to be obvious to her that I came over to do more than talk about a surprise party for Lisa. I didn't regret it and neither did she, I could tell. I asked her if I could return tomorrow with a vibrator and she said yes, and we had one more experience that was love making from A to Z. We both told one another that our evenings with our dates ended up with us in bed (she in his bed, me in my girlfriend's bed) and laughed about how we had done what we had done.

I am curious if anyone has ever done something like this, where you planned to cheat on your girlfriend (or boyfriend) and went through a plan you thought out and the other person was willing.