Cao Pi snorts another little chuckle, but doesn't elaborate on what it means. It could be a laugh at himself for slipping up, it could be denial that anyone should worry about feelings, or it could be a subtle admission that he doesn't care and isn't sorry. If nothing else he'll chalk it up to wine, which does make truth easy to tell.

"You think people don't take me seriously? Ah, if so...it matters little. I am not interested in being liked."

As long as they listen, which so far they do. Story of his life, really. He dismisses any concern with a little shrug.