So here’s the thing, someone who’s a thousand years old mentally would be quite intimidating, sexually, regardless of what they’re like physically. The thing about a lot of fictional “thousand year old” characters is that they still act like children, more or less.

There was a bit in Aeon Flux (or was it Ghost in the Shell?) where some kid (>16) was hitting on her, and she was like “oh you want to have sex? Sure let’s see what you’ve got” and the kid just like shits his pants. I think they end up having sex but in the aftermath it’s clear the kid was not in control.

So IMO you had a realistic “physically 9 but mentally 1000 year old” I think most pedos would not be into that.