I know everybody ships Kartis/Lord except me and I guess my mom who doesn't play Lord of Heroes, but listen here.
And insulting each other on a regular basis because they can't stand each other.
You can read it as sexual tension if you'd like, I won't stop your shipping heart, but imagine them working together and in the meanwhile at diplomatic meetings they talk like
Kartis: "Excuse me,bitch, could you pass me the salt?"
Kartis: "How kind of you, stupid cunt."
Lord: "Still resent me because I didn't allow you to die like the coward you are?"
Kartis: "Of course not, I am so happy I get to spend the rest of my life by the side of the crybaby who put my Knights in shackles."
Charles, pushing his chair back to get up: "Well, this lunch hasn't become awkward at all."
Rosanna, as she keeps eating: "Just ignore them. They are doing a good job at ignoring US."
Kartis: "Oh no, please, Charles, don't leave. We were very rude-"
Lord: "Wow, kind to Charles but not to me. Not THAT'S insulting."
Kartis: "Last time I checked he wasn't the one to throw my viceroy in jail-"
Charles: "DO NOT PULL ME IN THIS IDIOTIC BANTER OF YOURS."
Dhurahan: "Is... Is this a weird human thing I don't understand...?"
Aslan, putting more food in his plate: "Just eat and forget, Dhurahan. Just eat and forget."
Laphlaes, in a whisper: "What about the importation taxes? Didn't we come here to discuss importation taxes...?"
Lord: "Of course we were here to talk about importation taxes. I suggest taxes on products from Gallus get 200% higher."