I'm working on a NPC who was raised to believe he is half elf, half dragon (Wood Elf father, Red Dragon mother), but who is actually a full Copper Dragon. The character is supposed to be 26 years old, and when shapechanged into an elf he has the appearance of a 26 year old elf (an adult). Most importantly the character gets married in his late teens or early 20s. The timeline of his birth and marriage are important to the story.
My question is, how does dragon age work with shapechanging in 5e? If being 26 years old makes him a young dragon, does that make him a child, a teenager, or a young adult? Does it make sense that he's shapechanging into an adult elf? If he gets married at the age of 18 to an 18 year old elf, is there anything ethically wrong with that (did a child just marry an adult)? If he shapechanges at the age of 5 as a wyrmling into a 5 year old elf, then shapechanges at the age of 7 as a young dragon does he shapechange into a 7 year old elf? Then at again the age of 18 an 18 year old elf?
I'm starting to think actually making him a half-elf would be easier because then I could say he matured at the rate of an elf.