Hold on a second, Loki. You want to kill Caesar now because he . . . called Nakaba by her name?
You'd prefer he call her by some derogatory nickname? Or maybe just call her "Hey, you"? And even if you would prefer that, how the heck does he deserve death for calling his wife by her given name?
Also, Loki, how is it any of your business?
And oh, since you claim to be so fond of your princess, how about taking her feelings and opinions into account before you get violent? Because she's obviously fond of Angel Caesar at this point in the story, and you'll be hurting her by killing him, so yeah . . .