In a hypothetical society...

[Pegasus]

Let's hypothetically imagine a society where adult/child relationships were allowed, your AoA was 7-10y, and you had a romantic/sexual relationship. For 3 or 4 years, the child would be within your AoA, so they would be growing up in the meantime. And after it passed your AoA? How would you feel? What would that relationship look like?

[Walton]

I thought about this many times but probably would still be together after she passes my aoa and have kids of our own that we raise in the spirit of what we are so they know how natural it is to love children romantically and sexually

[PorcelainLark]

Probably like the relationship between a teacher and former student who were on good terms. Friendly!

[FairBlueLove]

Tricky, because s/he will go through adolescence, which can be mentally very transformative. If the transformation will not undermine our relationship, then, in case it were a girl, I would go the Walton way. And if it were a boy, then I can imagine something like what PorcelainLark said.

[WavesInEternity]

I always quickly warn any potential romantic partners of the time-bound nature of my erotic interest.

Those who loved me back made intensive efforts to prolong their attractiveness, which taught me that a girl who already has neotenous traits can maintain a youthful appearance for quite some time through a blend of exhaustive depilation, adequate hairstyle and fashion style, and even some cosmetic surgery. Along with the added sexual interest from the bond I share with her and from our intimate knowledge of each other's preferences, I have found that a hebephile like myself can find a girl attractive through her 20s and potentially even into her 30s (although I didn't have the opportunity to test that). It's far from easy—in my best relationship, I started failing in my role as the "spiritual adult" after about 5 years, when she was 25—and less than 1% of girls are truly suitable for it (they must be autopedophiles with sufficient neoteny), but it's possible.

In any case, the ideal scenario would be to stay close friends indefinitely after the physical part is over. I experienced something very close to this in reverse with my ex-girlfriend, as she wasn't attractive to me at first, before we got to know each other and she made serious efforts to look desirable to me. We were best friends for over a year before being lovers.

Unfortunately, that relationship also taught me that it can be immensely difficult to maintain a relationship after the termination of the intimate aspect. In that case, I ultimately failed in my promise to make her happy, and she ultimately betrayed me, even resorting to gaslighting at the very end. We're no longer on speaking terms, and she's no longer the person I used to be in love with. Even more sadly, in the hypothetical scenario you describe, I fear that there would be a high likelihood of the girl changing so much that I no longer recognize her as the person I loved. As FairBlueLove mentioned, adolescence can entail immense mental changes. Nevertheless, I would still choose to have the relationship, even if I knew it would end that way.

[Meiwaku_Mailing_Girl]

I always want to be a part of their life, even if it just means being friends. I'm not interested in lifelong monogamy, in fact I find it unappealing, so if we stopped dating but were still on good terms, that would be ideal.

[Fragment]

I've had previous platonic YFs that I'm still in touch with and on good terms with.

I'd hope that if I had a sexual relationship in a world where it was legal and not tarnished by parents, police and courts, that we could stay friends long into the future. Being best man at a YF's wedding is a dream I think I'm not alone as a BL in having.

[LittlePrincessLover]

The romantic/sexual relationship would end for me when they grew older. I’d still carry the relationship on as friends should they want that.

In such a hypothetical, I would have multiple romantic/sexual relationships with girls of different ages within my AoA. Hopefully I’d be able to carry on that ideal scene and it wouldn’t become a problem.