So I was talking to this guy for 4 years straight and I absolutely loved this guy, by the way it was a long distance relationship. We discussed that the distance did not matter and that nothing would ever tear us apart because we love each sooo much. So during our relationship someone randomly texted me a picture of my boyfriend with this girl going on dates, hugging, holding hands, kissing on the cheek and etc. I confronted him and he told me it was based on a contract for the university and sent me pictures of the contract and so on. He even sent me a chat with the girl saying that she had no feelings for him and she’s doing this for the university. So I was soo in love and I believed him. He told me the contract will be over when he graduates so he graduated and I was like yesss that relationship is finally over but guess what he made another excuse saying his step father forced him to continue it for a good family image. Which I didn’t believe at all so I message the girl he was “fake dating” and she was like that’s false it’s not a contract wtf. And I was like I’m making a group chat with him so he can make you admit that it was a contract so in the group chat he acted like he didn’t know me and that teared me apart. He said sorry but that wasn’t enough. Then two weeks later I messaged the girl talking to her on the serious note and she was like the guy you are talking to is not him that’s not the way he speaks it’s a “catfish” but I know it’s not because she sent videos of him talking and it’s the same voice I’ve heard over the phone. What should I do? He’s cheating on me and I don’t know what to tell the girl because she doesn’t believe that it’s him and I know it is.