From what you've written it sounds like sexuality in general is risky, which for young kids, I'd be inclined to agree.
At the same time, kids comics have infatuations, which don't necessarily become sexually explicit.
Yeah, and that's the interesting thing. An infatuation that is handled lightly enough to be kid-friendly can actually appear to be "friendship" or "admiration". It makes you wonder where the point is in a kid's mind where they start to connect what "love" is where it can possibly lead to.
A lot of that is socialization -- at least before puberty. As much as either side would like to say its hard coded or its social conditioning, no study points to one or the other, and no study refutes one or the other. My gut tells me its more physical than social conditioning, but that social conditioning plays a part.
That, and I don't know where crushes fit in. I had crushes before I new about the whole sex thing. I don't know if that was conditioning (I still remember the card game where young girls play by collecting boyfriend cards -- harmless pasttime for girls, or prep for trollops in training? You decide!)
I'm probably missing some context, but I see some folks are using Avatar as an example of the non-sexualized relationships, which isn't quite true because all the prep work has been laid down, and hearts are racing, sweatdrops are forming, and the kids are snogging!
Somehow, I don't think we'd be having the same conversations if Ang and Zuko started snogging. Although the deadpan blink blink from much of the audience (with roughly 10% of the population saying 'woot!') would be worth it :D
I did want to add something quick though -- I don't think every show *has* to hit on the issue. There's a BBC show called Torchwood that hit the subject full on. For friends of mine, after the initial "woah!" was past, it became like any other relationship in the series (complete with the one friend who wants "less snogging, more kicking alien ass", to which I'm pretty much in agreement)
Okay, just one more thing, and then I'll stop-- really, at least for this post. But so much of Avatar is about these kids growing up, and having deep emotional attachments (if only so they can have brutal fights, or those awkwardly tense moments, and the inevitable love cruelly torn away) that it wouldn't kill them to have a male character who had a romantic charge toward another male character. But there's so many other things that are just so enjoyable and fun about the series that I don't think the lack is a deep fault.