Frisk turns to Sans, staring at the gold teeth. A small frown appears on their brow, raising their hands they get his attention and began to sign.
"*huh? my gold tooth...?" Sans says blinking at the question, "how did i lose a tooth when i only have 1 hp?"
That eternal grin widens than laugher howls from his jaws. After a moment he stops and just continues sipping on his mustard like that crazed laugh never happened- A odd silence fell between them. In fact, the more Frisk sat there with their hand on pounding heart, made them wonder if that really was real.
"*not even my brother knows..." Sans, at last, said, lowing his skull slightly, "watch carefully bratling."
Frisk nods and waits.
Again more slowly, Sans brings the mustard to his teeth, just over where the gold tooth was; the skeleton glances at them from the corner of his eye socket, waiting for understanding to reach them.
Suddenly their normally none existing eyes grew so big that they could almost put Papyrus's googly eyes to shame.
"*that's right bratling. it's just stained." Sans confirms grinning madly, he then bought his finger to his sharp teeth, "shh. never tell boss."