"...You really just sound like a bad imitation of yourself right now, you know that?"

It's actually kind of disgusting. ...Well, this whole thing is disgusting, but this in particular is bothering him now. Then he gives a quiet snort, glancing away as he realizes something.

"Kinda reminds me of myself before that flower got burned out. You really don't realize there's anything wrong with you right now, do you?"

He's not even really talking to Sans at this point, let's be honest.