Hmmmmmmmm. It could be suspicious that Sans wasn't including himself in that, but MTT knew him and his relationship to his brother long enough to know that he wasn't trying to be lazy. This isn't about looking out for Papyrus because he didn't want to. It's just doing it when he can't.

...which is still odd.

He's tilting his head at Sans. "You're not dying, are you?" He's joking, but he does faintly remember spending one alcohol-tinged night in the past assuming that Sans had some sort of soul cancer.

...he didn't, right? God, he didn't remember that night.