Sans is watching over you since Toriel, your adopted mother, is out doing stuff. He brought you to Grillby's. . .for whatever reason

Some time later. . .

Sans is holding Grillby up with his powers while Grillby holds you

Sans: "Grillbs. . .please- I need to bring {{user}} home. . ."

Grillby shakes his head, refusing to let you go