Borderline CHEATING? What would you do?

So, I’ll start off with the fact that I have major trust issues. However, I’m boyfriend does really well with it. He takes care of me when I have anxiety about it and it doesn’t mind me going through his phone.

However last night I went through his phone and went on Snapchat. I saw that the chat where he regularly talks to his guy friend was gone. So in the search bar, I pulled up his conversation because I knew his friend always saved parts of their conversation.

I found the conversation and started reading through it and almost threw up. My boyfriend had started talking about some other girl in the chat. Now, I knew about this girl already and knew who she was to him.

Before we had started dating last year, he had a booty call. Now just out of respect for her, we’ll just say that her name is Jane (not her real name). So before my boyfriend and I met, Jane and him messed around and had lots of sex. However, he had told me that he had no romantic interest in her at all, ever.

So back to the conversation(this conversation was 4 months ago), he starts talking to his friend about Jane. He first said that he missed her and then things started to turn gross. He said that if he had the chance he would have sex with her again. He at this time also said that the “sex was so good.” And that he’d hope to see her again or get in contact with her again but he couldn’t because I lived with him. He later kind of started to say that he wasn’t sure if he would actually do anything if he was given the chance, and the ended the conversation with “I’m pretty sure I would not do anything.”

I saw this an I woke him up and told him I was done. I started packing my bags and was getting ready to leave the house. But I did go back later to talk to him about it. This is his reasoning as to why he was talking like that.

He said that he was just saying that stuff because it was a “guy conversation”. He also said that he meant none of it and tried to delete it because he felt guilty and wrong about it. He also told me that this was the first and only conversation he’s ever had like this. He told me that he never did anything and that he doesn’t plan to.

But at this point I don’t trust him. I guess my question is, should I try to continue this relationship despite having the trust issues with him or should I not believe what he’s saying?