He betrayed my trust ..

My boyfriend texted me to tell me about a woman that has been trying to get with him . He texted me a screenshot of what she had said... and then he told me that she sent him nudes. Immediately after he told me that I knew he was not telling the all the details ... this woman knows him and I are together ( long distance) but still decided to send him nudes I just felt in my stomach that something wasn’t right and then it came out that he was saying sexual things to her possibly sent her nudes as well but I couldn’t bring myself to ask if he did or not . This whole time I’m thinking it’s all this woman’s fault that it’s only her who was the wrong one but that’s not the case now . I just don’t know what to do . All I can feel is hurt and anger at him and her both but more so him because he allowed this . This woman lives in his city and it’s making me feel a lot worse . What should I do ?

He was crying and telling me that he didn’t want to lose me .This stuff only came out because I asked him if there was anything that he said to this woman that he needs to tell me now . He was never going to tell me this .. even though he said he was going to tell me because he felt guilty .