I’m confused

So my ex and I have been broken up for a few years. We recently started talking again after running into one another. We’ve both moved on with our careers and made something of our lives. It’s nice to know that we’re on friendly terms again. 😊

I noticed the past few times we’ve talked casually that he keeps bringing up sexual memories of when we were together. Talking about clothes I wore or things we did together. It doesn’t bother me talking about this stuff because, I mean, it happened. Lol. I was there. I’m just confused as to why he keeps bringing it up. He was the one who broke it off between us. He says because he really liked me a lot and then one day he didn’t feel that way anymore.

I don’t know what to do about it.