The dust rises around them, and Sans coughs. Oh, haha! What's this? Unexpected. It seem to catch him a bit by surprise, but not in a bad way. He looks around at the sparkling dust, then looks up at Papyrus, his step wobbling slightly as he bears down on the other skeleton regardless.

"Then it is granted," Sans says, leaning in close even as the dust seems to make his movements slower and sleepier. "Your brother... is yours. And you may perish in this storm together."

Sans will slump forward, his visor dropping from his hand onto his the ground. Still, he manage to keep his eyes upward, even as he stumbles.

"That... is my payment to you."

He collapses, then - either into Papyrus's arms, or onto the floor. The Mother's presence is gone.