I'm probably overthinking

Okay....so....serious question. My husband and I opened up to each other tonight and this is on my mind and I basically just want to see what others think about this. I asked him about a girl that he dated in college and I asked him if he could see himself with her now, his answer was that they never had any bad blood. It was just one conflict that broke them up then we got together (we've been together for 5 years and married for 2 years). But he said that if she is the same person that she was when they dated or better then he could see them working out if God forbid we didn't for some reason.

So my question is, can you see yourself with one of your exes? I don't want to let it bother me because he opened up and I don't want him to feel like he can't do that with me. But I am curious. He said that he knows that me and him are meant, and his heart is with Me, and he's committed to me. I'm probably just overthinking...idk I just had to put this somewhere because I have no one to talk to about it