Him in golden armour.
So natsu didn’t particularly want to serve his country, but he believes in the monarchy (i.e Lucy) and wants to amount to something, grow up to be a great, honourable man.
Pursuing a military career is ideal given his low birth, his only real chance at achieving this goals.
She already know he’s gonna rise through those ranks like no other man before him and get noticed very quickly.
and his superiors want to make him an example, and inspiration to all the young men in the land who hope to improve their station in life.
so they ask him what he wants and he says he wants to achieve the greatest honour possible, and he hopes to be a knight some day.
boom, he’s the youngest man to serve in the royal guard because what’s more honourable than protecting the monarchy?
but natsu is unhappy in his honorary position, he feels it was handed to him.
he takes his duties seriously, but it’s far too cushy a job for someone with his ambition and energy and he gets restless a lot.
and then someone tries to abduct the heir to the throne. Lucy.
and long story short they wish they hadn’t tried because natsu saves her single-handedly in spectacular fashion.
after this he has a renewed sense of duty and responsibility, because while he may not see a lot of action his presence is still important, and he feels a little better about things.
Lucy also get to knight him for saving her life, and it’s a great day for the both of them.
it’s around this time Natsu is appointed as Lucy's personal guard.
which is kinda awkward because, while he’s the only one in court of a similar age to her, but she barely spoken and he’s so serious always.
also he’s a farm boy, kinda rough around the edges, and doesn’t have the best manners exactly he’s kinda clumsy when it comes to etiquette, which is just very lovable tbh.
also she can tell he’s grumpy about having to follow her around all day, so she make an effort to be more active for his sake, hunting, riding, etc.
and when she can’t even kill a rabbit he realises she have been doing all these things for his sake and he gets really blushy and shy and it’s adorable.
and he warms up to her a lot more after that.
but lucy still make him sit and drink tea with her just to annoy and embarrass him a little, so he doesn’t forget who’s boss lol
She didn’t get to have much of a childhood, and Natsu's still a boy at heart, so they play around a lot.
Sneaking around the castle at night and playing hide and seek in the castle gardens.
Imagine natsu getting in trouble for letting the heir to the throne fall out of a tree.
or when she hurt her ankle and he just picks her right up and carries her inside to see the court doctor.
or helping her practice dancing for an upcoming ball and realising not only is he a brilliant dancer but he really, really loves it.
and when the two sneak out to the ballrooms in the middle of the night to dance, or just dance in your chambers, or in the gardens even.
but in official capacity he’s still very serious and dedicated.
Lucy loves acting cute or pulling silly faces when no one else is looking to try and crack his facade.
and he will tickle her for it afterwards.
but honestly he adores her and would give his life to protect her.
She love him and she know if there was ever a war he would charge in head first, which provides her extra incentive to keep the peace.
honestly, being royalty isn’t easy but she need to make it look that way.
and at the end of the day natsu is there to love and support her, and she can finally be just herself for a little while.
