"Daddy?" cries out the voice of a young boy. Gaster turns his attention to the sound, chuckling quietly.
"Daddy!"
Gaster responds in his iconic, yet unusual way of speech, " ✌❄ ✋💧 ✋❄📪 ✌ ✡ 💧 💣✡ 👌 ✡✍" Or, as translated back into English, "What is it, Papyrus my boy?"
"Sans is buwwying me again, daddy!"
The pre-teen skeleton scoffs at his toddler brother, rolling his eyes. "Am not…" he mutters to himself. Despite it being barely audible, Papyrus catches what Sans had said. "Am too!" the small skeleton replies.
"Am not!"
"Am too!"
"Am n- "
Gaster grabs both boys by the collars of their shirts, sending them to their rooms. Little Papyrus lets out a whine of disappointment, while Sans simply scoffs yet again. The heavier, older skeleton brother plops down on his bed, sighing. What am I going to do with him?, he thinks. What am I going to do… with me?
Young Sans suddenly jumps, hearing the distant screams of his father. Despite his father restraining him to his room, he manages to teleport downstairs. The prepubescent skeleton calls out his father's name, obviously concerned.
"Dad…?"
He hears the screams getting consistently louder each time, and traces the sound coming from the basement where his father's laboratory resides. But dad's experiments never go wrong, Sans thinks. What could have happened? The young skeleton cautiously approaches the basement as the screaming now gets slowly dimmer. A face a great concern is seen on the boy's face; Sans appears to be on the verge of tears.
"DAD!" he cries again. No answer.
"…Daddy…"
Everything goes black. An adult Sans wakes up, shaking. Papyrus is by his bedside, comforting his older brother.
"Everything is fine, Sans," Papyrus says with a smile of sympathy. "After all, it was only a dream, right?"
Only a dream.