My partner and I were on a trip and stayed at a hotel. While on this trip, at first it started out for relaxation, but it turned out to be business, we ended up at a convention. The luxury hotel then changed to a scene somewhat like a prison, very dark and gray. That evening there was to be a dance. My partner and I were in our room having incredible sex. There was a knock on our door, I got up in the nude and opened it. The person at the door wanted my partner to help sell tickets from the room next door. He got up, dressed and left. I also got dressed and followed them. The one person told me to monitor the people walking in outside of the door. I got suspicious , so I walked in. Shockingly, I saw my partner, who is a man, kissing another man. I was so upset, not because he was a man but because he was cheating on me right after we had incredible sex. My partner did not say one word to me. Later that day we had a business meeting and he was sitting next to the one he kissed. All I said was "I really need to talk to you."