My boyfriend’s excited over someone else

I don’t know if I am just overreacting to this situation but it makes me feel not wanted.. or at least not wanted as much as she is. My current boyfriend has not been in a relationship before, even if he has been it wouldn’t bother me. But.. there is this one girl who he had deep feelings for. I know her, even went to her wedding. They are still friends after many failed attempts on his part to start something with her and she was in a relationship at the time. Now, she has cheated on her now current husband many times and I’m getting a feeling my boyfriend still has feelings for her.

Today, my boyfriend and I were out shopping and he got a text from her saying,”What are you doing at target?” He absolutely freaked out. He didn’t even tell me what was going on or who texted him or anything. He was looking at his phone with the biggest smile I’ve ever seen and started looking around for her. He would run through aisles and as I’m starting to feel embarrassed I just stop chasing him. A couple minutes past and he comes back to me literally panting like he just ran a mile. He says she just texted him saying that and that he couldn’t find her anywhere. I don’t know why he cares so much as they really aren’t that good of friends, of which I know. And sometimes she calls him over the phone to cry and vent about her husband and every time he’s rolling his eyes and giving vague answers like he’s ‘annoyed’ but why else would she feel comfortable calling him to cry to?

Am I overreacting? This is just so uncomfortable and when I told him that it made me feel that way he just said she’s just a friend who cares? Well. I care. I love him and seeing him get so overly excited about her made me sick. Am I in the wrong for being upset over this?