Or a Scorpion NPC. One not-quite-random poisoning for the win.
I have to question the DM also. If you have a group of courtiers, then there should be a preponderance of interaction encounters, not fights. Should the disruptive player be turning the interactions into fights for no good reason, that should quickly come back to haunt him. Should the DM not do that, then the DM is the problem as much as the player
Insulting in character can be part of the game, but any insults out of character should be immediately stopped. That is not acceptable behavoir.
One thing you could do is arrainge to have the whole party in a social situation, and then use the fancy courtier skills to make him look like a buffoon. Should he take exception, then see Filcher's comment.
