My (27F) boyfriend (25M) still follows girls he was attracted to on Instagram.

I want to start of by saying that I don't need anyone being rude and calling me immature, insecure, etc. I am actually aware. I'm just looking for someone to get through my brain that it's normal to be following people you were once attracted to and that doesn't mean that you're still attracted to them.

To give some background: I never thought much about the girls my boyfriend follows. I just assumed they were friends/people he knew from his hometown. However, I started to notice that when there was a girl's story and I was next to him, he would skip it, but once I was out of sight, he'd go back and watch it. I asked him if he was ever attracted to any of the girls he follows, and his initial reaction was "which one?" So I just said all of them. He brought up the girl he was into and tried to have a thing with about 2 years, but I already knew that, so I said aside from her. Then he went all quiet, and eventually said "how far back?" I didn't really care, I was just looking for an answer to my question. He then says "2 or 3... back in high school." But his initial reaction makes me wonder if it really was back in high school or if anything is more recent... maybe he's still attracted to them. I mean, I just don't get why he'd hide opening their stories from me when I've never said anything for him to do that.

TL;DR My boyfriend was being secretive about opening stories from girls. I asked him if he was attracted to them at any point, and his answer wasn't very convincing that they aren't recent attractions.