Help

I am going to make this short and simple. I miss him so much. Ages ago he told me that he just went out with his friends to the park and he saw this girl but he claimed that she was “drunk” and she was trying to hit on one his friend’s but she left afterwards. I didn’t believe him since before we started dating, he used to text other girls whilst we were still texting, but then he did change later on, so I’ll give him that. Later that week when he came to mine, I was getting suspicious as he wasn’t being his usual self, so when he went to help my dad out with some things, I went through his phone. We basically are allowed to go through each others phones and we have each other’s passwords as-well so I was hoping I wouldn’t find anything. I went through the messages of him and his friends just to find out that the girl was hitting on him.I don’t know if he kissed her or not because in one of the texts he said “I should’ve kissed her back” but he was entertaining the conversation and told her his single. That was the end for me since I have high standards and don’t get with anyone that disrespects me even though I got with him? I don’t know what’s going on in my head right now since I have to see him in school everyday as-well and he does talk to me in school but it just hurts so bad because I know he still wants me but I don’t know how to feel.