It is probably very telling that this shuts Kevin up damn quick. 'He already had his mouth open to say something snarky and he shuts it so hard his teeth click audibly' levels of quick. There are a few things in life that Kevin takes far too seriously to ever joke about. Murder is not actually one of them. Knighthood is.

"...I was Sir Kevin Regnard at home, you should know, then," he says at length, his voice much quieter now. "I earned my title properly."

And lost it just as surely. He's toyed with the idea that he might manage to redeem himself just enough in this place to get his "sir" back someday, but his heart's never fully committed to it. That isn't something you can declare for yourself, and all the people who actually understand why he'd need to reclaim it in the first place would probably tell him he deserves it without a second thought.

For Kylo to bring such a thing up -- suddenly the conversation can't be completely about lightsabers anymore.