
Well... I mean if you don't like the age gap between these two, you'll probably be disturbed more by even larger age gaps between the other characters (like several hundred years), though I don't know if you can judge it with human standards as it's an elf and dragon, lol.
It's a fantasy series and the two main characters are both adults so I don't really see anything wrong with it, but that's just me. I understand it just might not suit everyone'a tastes.

To be honest, at the beginning I didn't like it either, but seeing how they can be good for each other, I'm changing my mind. Besides, this is a fantasy world, age gaps are pretty much irrelevant when there is magic . If we attached ourselves to our world's concept of age, we could never ship any member of the immortal / long lived races, such as elves, dragons, dwarfs...
Can someone convince me to read this..?. The age gap keeps on weighing in my mind...