Cuddling Is Cheating

My boyfriend invited a girl around to his house in September 2021 and had sex with her. He says he was lonely as we were long distance, but she's seen him over a year later. She described sexual things that I know my partner does so I believe her. The bad part is he used to sleep with this girl when he was 17. That's even worse. Even messaging another girl with sexual intention is cheating in my eyes. So you can imagine how destroyed I am. In the months leading up to finding out this out, I also went through his phone. Oh, for fuck me. From all, delete verification codes from Tinder. How stupid are you? Come on. Clean