Is AUTHOR wrong in the post ? POST : Background: I’m 26f and engaged to a guy I thought was the one. I love him so much it hurts and I can’t bear the thought of life without him. We have a great life together.

One of his fantasies is me with another girl. He’s said he’d love to see it, he loves to hear stories about the dew times in college i kissed other girls and he loves it when I tell him stories about other girls while we are having sex. 

I went on a girls trip this weekend. On the trip was a very cool girl I’d never met before and she and I stayed in and drank wine while all the other girls went to a movie and club. One thing led to another and we ended up completely booking up in the Airbnb. It was very fun and felt amazing but we both agreed that it was just a hook up and no emotions, it wouldn’t happen again and that the only people we’d tell were the respective men in our lives because her husband has similar fantasies. During the whole thing I was so excited at how turned on my fiancé would be when I told him what happened. 

Well just got home and was so happy to see him and i told him what happened. He freaked the fuck out and told me I cheated. I asked him how was it cheating if he’d tacitly given me “permission” by telling me hundreds of times how much he wants me to hook up with other girls. He said I should be smarter than that and it was “just pillow talk.” I cried and cried and told him how sorry I was but I did it “for him.” He said that was bullshit and stormed off and the last thing he said before apparently turning off his phone was “not coming home, need to re-evaluate if this is the relationship for me.” 

I’m devasted but can see this going both ways. I didn’t mean to hurt him in fact just the opposite but part of me sees his point. 

Am I the asshole here? Please help me see this more clearly. 