okay I know this is stupid

But I have this vibe from a girl on my bfs insta the thing is he likes every single one of her pictures. Now I know that's childish but hear me out this girl is close to his family and he's been alone with her on a beach. His parents claimed they kissed then when we were dating but my bf said they didn't. So that's why I feel off. I brought up my concern since they used to text and she had a nickname for him. She always asked how his gf was and also asked him to hangout. He assured me it was nothing and I was being crazy. I know they haven't talked over text since last month since I'm very insecure and checked his phone. We are long distance and I don't want to be so naive that I miss seeing him cheating. Well then today he needed me to go on his bday insta since he was having troubles logging in and saw he likes her pictures again. It upsets me so much because I will admit she is very pretty and looks like she has a great life. I just wish when I told my bf to stop taking to her that he would have dropped all communication and listened to my concern. I don't know how else to approach this.