Why not? Kalecgos seems to be a really nice character.
I would date a dragon too, if they were existent and if I happen to like one.
She should have taken up Kael's offer for that date in Silvermoon.
Not necessarily. I've met children who seem like adults and adults who seem like children. Physical age doesn't define a person's maturity, and maturity is really what counts when you're trying to define how old someone feels.
And keep in mind that counting physical age by years works both ways. An immortal dragon might still be a child after thousands of years.
That would make all humans seem like children to night elves and draenei.
You are confusing maturity with age. Shorter lived races would definitely have less experiences, but that doesn't influences in their cognitive functions and bilogical maturity.
Of course, longer lived races could call the "children" but their only argument would be bigotry.
If you can get past the fact that you're dating a Dragon the rest is easy, they can all become Human(oids) so nothing strange about that part.
As far as children go, half-breed dragons (human with the ability to turn dragon... having it the other way around would be a very rough .. and scaly... labor... so)
It's not just about maturity, emotional or physical.
Shared life experiences are a HUGE deal. That's why Paris Hilton doesn't date Joe Hot-Pocket or when they do - like Larry Burket and Liz Taylor - it never works out. Or why people who graduate college are more apt to be with other people who have graduated college or heck, even why inter-racial couples are so rare.
Even if someone has experience paying rent, they may not have faced a choice between eating anything but ramen for the next week or being kicked out of their apartment. As you extend this particular line out over time and add more and more experiences it becomes that much harder to relate to people who haven't had similar ones.
Think about it, Kalecgos at this time has probably buried multiple friends - do remember dragons take a very active role in the day to day life of all the "mortal" species of Azeroth. He's Highlander and Jaina is just another brief fling, they'll be together for a few years but even if it lasts out her entire lifetime to Kalecgos she's nothing but "that time I spent about 60 years slumming it up with this hot human piece of ass." (Ok, yeah, I'm paraphrasing some added callousness in there pretty hard.)
If you don't believe me on this or want to just say "it's because the brain of a 19 year old isn't fully functioned" that's fine, but truth is that maturity and even empathy doesn't really have a lot to do with mate selection and success of a relationship. The ability to straight up relate to someone, to be able to talk to them about your cares, worries and future does.
If one party in a relationship is effectively immortal then there's just no way to bridge that gap as time passes.
Well, I was including life experience when I said maturity (that's part of emotional maturity).
It's hard to say how accurate this is, though. We humans don't live tens of thousands of years. Humans in general live for roughly the same amount of time as each other. We don't have any real-life precedents of a relationship like this. We can make assumptions based on precedents that do exist based on our own lifespans, but the time gaps are going to be comparatively tiny.
To Kalec, his relationship with Jaina may just be a brief, forgettable moment in time a few thousand years down the line. Then again, a being that lives tens of thousands of years may not perceive time the same way we do, and his memories of Jaina thousands of years down the line may be very comparable to how a human would feel only a couple years after their spouse died.