Me Vs her,can this be considered a red flag?

To keep it short, my bf was showing me some pictures of him, and when he was going through different albums I happen to see an album cover which had the picture of his ex wife,besides this picture they send text messages to each other/communicate on a regular basis (I really don’t know who starts the message or conversation) and he even sees her in person when she needs a favor from him, should I feel worried an concerned or not. he is a great person with me, treats me very nice, but I want him to forget about her an move on. I get they where married for quite some time but they don’t have even have kids together so I don’t get all the communication between them. She is 58 and he is 46, I am 30.

Plus the WORST is that yesterday we were together, and when we were going back home, he was checking his messages and he then tells me:'' it was my ex wife she texted me that her car broke down'' she is with a friend. and then when we get home he tells me let me call her, so he goes outside, why in the world would he not call her in front of me? you see this is what makes my head spin around, , the other thing that I don't get why the hell does she have to call him to tell him that? and the worst part is that he sometimes goes an caters to her needs (Obviously he did not that day ,he was with Me), I feel he is a fool for being a way to nice after a divorce people usually don't get this along after a DIVORCE! Honestly I really don't know what to do, if just get it over with and have a conversation with him an tell him to forget his past and move on, I just cant keep swallowing my thoughts over an over. this has to stop or I am out. Why in the freaking world is he with me if lets say he still ha feelings for her? does not make sense at all.

I talk to him about it and he understood, he seemed very sincere and told me he was really into me and he felt very good being with me and that if i did not like something that he was not going to do it anymore. that's why he is buying this house so we can plan a life together. that if I left him he would be deeply hurt. I hope he is not telling a lie or something. To be honest he seemed sincere to my knowledge.