Which is why he's not physically doing anything now just thinking and waiting for your guys response. IC he thinks your guy is an idiot because who kills a prince in their bed in the middle of the night with his servant only on the other side of the door, guards patrolling the grounds and castle and a whole host of weaponry at his disposal if he does somehow get loose. It would have been more intelligent from his point of view to kill him at the party, no fuss no muss and since there were so many people coming in and out of the castle virtually no chance at being seen unless an amateur mistake was made. This is am an whose had multiple attempts on his life and has to dress up just to appease his fathers vanity. He has lots of time to spend on how he'd kill someone of his standing without getting caught and he's the one who usually foils the attempts by not being an utter weakling.

Also the way he's holding the knife id rather...unusual, if you were going to cut the vein/artery you'd hold the blade flat to the throat horizontal to the jaw line and with pressure on the sharp side of the blade. Not pointing up where if someone did jostle you you've only got a fifty fifty, if that, chance of pulling off the move you wanted. Where as the other way is quick, clean and without as much of a chance of failure because if you were knocked/thrown off then you still had a chance to cut deep. I've played a lot of assassin's in online battle arenas, rps and in larps so Iv'e got the whole killing without too much struggling thing down to an art (IN GAMES) lol.