Sans can definitely appreciate how the act of breathing can do a lot to steady a skeleton even when they don't technically need to. Just the feel of air moving through your skull could clear your head in more ways than one. Trying to sit up right now, however, is much less understandable, and he moves to put the kibosh on that idea quickly by pushing the other Sans firmly but gently as he can back down. Otherwise, he waits patiently while his other self gets himself together.

...even if the other Sans' priorities actually make him laugh aloud, in the end. It's a somewhat hysterical sound that he tries unsuccessfully to muffle with his other hand.

"trying to get her away? pal, she's fine. from where i was standing, she was kicking the big guy up one end of that hall and down the other." He shrugs dully. "maybe she'll finally get him out of our hair for a few days."