How to say "I love you" in different Korean speech levels
I have a historical fic set in Korea. It's basically about the illicit love between a young prince and a rebel boy. Both are between 18-19 years old.
I would like to include a scene of them confessing their love to each other, basically blurting it out, and to emphasize their different positions in the society, I'd like to write the confessions in Korean. And this is where I hit a problem: I don't speak Korean, and I only know that there are different speech levels in Korean.
Therefore, I would need someone to tell me,
1. How the prince would tell the rebel boy, "I love you"
and
2. How the boy would reply to the prince.
So basically, how would a royal say these things to their subject, and vice versa.
The story is set in the Three Kingdoms era. As for their relationship, they treat each other as almost equals and act relaxed in each other's company. The rebel boy is a bit of a snarker, so his response might be a little sarcastic and he might like teasing the prince about his royal position, while the prince would definitely be serious about what he says.
I've tried reading the Wikipedia article on Korean speech levels, but since I don't know any Korean and the examples used didn't include the verb "to love", I am at a loss. I've also tried googling "Korean speech levels", but, once again, knowing about the endings doesn't help me since I don't know how to add them to the root word. Nor do I have any Korean speaking friends who could help. Also, I feel like this is a really culture-bound question, so only knowing the language but not the cultural dynamics might not help.