My boyfriend liked his female friend’s thirst trap…

Is that normal? She posted it on her close friends story. They have a history, one that he downplays. He says he was never really into her, but that she’s tried to hit on him when they were good friends 10+ years ago. They’re really funny people together so I don’t hate her or anything. She’s cool… but I do wonder why she doesn’t really set a boundary for things like this? Why post an obvious thirst trap on your close friends story? Like bra photo. Not bikini. Big titty bra. Should close friends be liking it? Why not just post that to her main story if she’s that thirsty? Why did he like it? He totally admitted to it when I asked if he happened to see the photo. So I know he’s not trying to hide anything. We’ve never talked about her being in our relationship, so I’m just a little bit surprised I guess. Is it normal for men to like their female friends’ thirst traps? Asking for a friend!