I was at an event with friends and a female I was dating. We were at the event and while I was talking with my friends I realized, that she wasnt by my side anymore. I saw her talking with another Men. I know her from a Dating-App, so I expected that something worse like that would happen.

I saw her engaging in a conversation with the another Men, both became slightly physical and I saw them doing something on the Phone. I have no Idea what they did there, but I think they exchanged numbers. I pretended that I didnt see anything and decided to go over and introduced myself friendly. Later as he walked away, she told me that I had a look on my face and that I dont look well. I told her I was fine

Just by observing her and through her act I was sure, that she has multiple Guys. I made sure, that I have my fun at the event and pretended that everything was fine. After the Event, I told her kindly to have a Good night, I didnt save her Number and ghosted her. Initiated Hard next.

Any thoughts/views/improvement? I thought at the moment I should have walked away as I have seen her with the other Guy, but on the other side I wanted to stay at the event and have my fun.