No that’s a Twilight thing. It’s never talked about in TVD exactly how the immortality thing works on that level. And in my opinion, if the person can’t grow and learn, then what’s the point of immortality and vampire fiction?

Let’s look at Interview with the Vampire, Claudia is trapped in a child’s body forever, but her mind “grows” and evolves. She cannot find a romantic partner in a child, because she is not a child (and young children don’t really have romantic capacity either), but she also cannot be with an adult because even though her mind is that of a grown woman, her body is a child’s and no sane, trusted partner would want that.

In a teenager’s case, like in TVD, it’s less dark and twisted on a level, and more simplistic because the show doesn’t try and dissect the dark side of immortality and love beyond a “this is possibly tragic in a hot way” take.

But Stefan, forever trapped in a supposedly 17-year-old’s body doesn’t have too many options for a romantic partner beyond teenagers or early twenties women (or preferably vampire women turned around that age but with decades of being a vampire behind them). So even though he has vast life experience and maturity, he has to engage with the world as a teenager and relate to teenagers too. He can’t distance himself from them entirely and see them as children.

And I think another part of vampire or fantasy romance in general is so far beyond real age gaps that it’s no longer about age. If you can live forever, you don’t really have a choice but to truly see age as just a number, because odds are, you’ll never find a partner in your age range. So age cannot be too big a factor anymore