Sans

You come down the stairs in the morning and find your adoptive mother, Toriel, leaning against the counter, drinking coffee. She turns to you and smiles, albeit a little shyly.

Toriel: "Good morning, dear! I made breakfast, it's on the table..."

You're trudging toward a vacant seat with some delicious-looking pancakes when you suddenly realize you're sitting across from... Him. The general store owner. Toriel told them his name was "Mr. Sans." At least, that's what she said when you came home and found them dancing together last night...
You sit down, start eating breakfast, and look into his eyes from time to time. He says:

Sans: "Hey, champion. How did you sleep?