Friend's history with Boyfriend?

My boyfriend recently introduced me to a friend of his. She seemed super cool, and invited me to hang out. We hung out a few times, and she’s a really cool girl! We get along great!

Last time we hung out, we were talking and she told me a story which included her telling me about a week-long period, from a few years ago, when she and my boyfriend liked each other. She told me that they had made-out, that he wanted to have sex, but that she hadn’t wanted to since they were good friends. Nothing ever happened after that. I think she was just trying to be honest so that she wasn’t hiding anything from me.

This all happened long before my boyfriend and I started seeing each other, but I felt momentarily uncomfortable. I felt like I had to hide the fact that it was the first I was hearing about it, and I really wish my bf had given me the heads-up.

I don’t know if I’m over-reacting about it. I now feel weary about hanging out with the two of them together which I know is silly since their history is so far in the past, and she is now in a committed loving relationship and all.

I thought that I wanted to say something to him about it, something along the lines of “please tell me next time you introduce me to someone you’ve hooked up with”. Because mostly, I think that finding out from her made me feel uncomfortable, like I was finding out a secret he’d been hiding from me.

I really love him, I know he loves me too.
Am I way over-thinking it? Should I forget about it? Or can I say something?