"I do not require amusement. I require a latte." Even without the Force he knows that kind of falsehood. He uses it pretty frequently himself.

He's normally fine with it, it's way of keeping things civil between people who otherwise hate one another... and he hates a great many people. Including the boy in front of him.

Even in the best of times he sometimes 'slips' with his ability to control his power. So, even though he's technically trying to be on his most civil behavior his subconscious is just not cooperating. Unless Yukikaze has some natural resistance to the Force, he may notice a certain tightness starting around the general vicinity of his throat.