Is this cheating

This girl who is a mutual on social media sent me a screenshot of her cousin and my boyfriend talking on Instagram. He told her that he had a girlfriend repeatedly but this screenshot of him saying they can still be friend after she sent an ass pic is bothering me. How can he keep speaking to her if she obviously is flirting w him. I’m so hurt and I don’t know what to do. The girl who is a mutual is close to her cousin, and the cousin decided to show who she was speaking to and it happened to be my boyfriend (who the mutual sees often in my posts. Here is the screenshots from the cousin and tell me what you think. Is this considered cheating? I feel like it is cuz he still allowed access. Look at how he calls her pretty and puts laughing emoji’s after she sends the ass pic of herself