Boyfriend is cheating on me flirting and meeting other girls

Me F [29]I found theatre tickets in my boyfriends M[29]pocket.he took out some other girl to a movie. When i confronted him first he said he got it from the road and after pushing him further he said he did book the tickets he did use his scene card but he never watched but the ticket was teared when i went to check cineplex they said it is a physical ticket and it cannot be scanned if its used they will tear it on the side.

Tldr

Anyone can help me to really find what is the truth am so dumb i know am still trying to find a chance trying to see if he is really worth a second chance.we have been in a relationship for 3 years now. I donwant to walk out so soon i wven caught him using dating apps last year but he said he is buidling an app with an IT guy so he have installed all that. He even brought his mum and sisters to back him up. I didn't research much when i found about the app.