I couldn't leave the story like I intended. The idea of Dadster was stuck in my mind and I wanted to write it...though it didn't go as planned...take this as the optional ending, since I'm 99% sure they're all OOC.
Sans glared at his brother over the dinner table. The night following Papyrus' discovery of Toriel they had a small dinner party with Undyne, Alphys and Mettaton invited. The occasion of the party? Sans and Papyrus' dad, Gaster, had made it out of the void with a little help from Alphys.
"What?" Papyrus asked innocently.
"What are you grinning about? What did you do?" Sans questioned. Normally he wouldn't mind Papyrus grinning, but considering the events that happened earlier that day, Sans felt the right to be suspicious of him.
"Nothing, I'm just happy our friends are here" Papyrus grinned wider.
"I KNOW you did something. Tell me." Sans demanded.
"You'll see" Papyrus smirked.
Sans was about to argue further when they suddenly heard the doorbell ring. They weren't expecting anyone else.
When Sans noticed that Papyrus was somehow grinning even wider he realized what his brother had done.
"You didn't."
"I did~" Papyrus chimed.
Sans jumped out of his chair and pushed past Undyne, who had originally offered to get the door. The action surprised everyone in the room -except Papyrus-.
"Knock knock" Sans heard Toriel call.
"Who's there?" Sans nervously called back, everyone at the table was watching him.
"Luck."
"Luck who?"
"Luck through the keyhole and you'll find out!"
Sans blushed and chuckled a bit before opening the door, "I hardly see that as necessary."
"I spent most of the afternoon trying to think of one" Toriel giggled.
"So...what have you got there?" Sans wondered.
"Oh!" Toriel seemed to forget about the basket she was carrying, "your brother asked if I could make a pie for your party after I told him about how I baked a lot."
"For one, how much did you two talk about while I was unconscious, and for two...did you make a separate one for me?" Sans asked hopefully, "lord knows how long I've been waiting to try one of your pies."
"Of course, what, you think I would forget about you?" Toriel giggled, leaning down and lightly kissing Sans' forehead.
Sans' audience covered their mouths in a fatal attempt to not laugh as they watched their entertainer's face burn blue.
"Do you mind if I come in?" Toriel asked politely.
"N-nope" Sans squeaked. Everyone watching fought even harder to muffle their laughter.
After Sans let Toriel in, he noticed that they had see the entire thing and let out an embarrassed squeak before pulling his hood over his face in an attempt to hide.
Out of a small gap in his hood, Sans saw his father waving him over. What did he want? Sans didn't know, but he needed a distraction.
"What is it dad?" Sans asked, trying to force himself to calm down.
"I didn't know you had a girlfriend" Gaster signed. Gaster was mute, he could only speak through sign language. Luckily both Sans and Papyrus knew it.
"She's not my girlfriend" Sans blushed furiously.
"Oh? But you were flirting" Gaster looked confused.
"N-no d-dad" Sans shook his head. He felt like a little kid again.
"He accidentally proposed to her earlier, then fainted, that's why he's so embarrassed" Papyrus explained. Loudly. Everyone heard. The laugher they'd thought they'd beaten came back with a vengeance, and this time they didn't hold it in.
"SERIOUSLY?!" Undyne howled.
"I-I-I'm s-s-sorry" Alphys stuttered as she giggled.
"I NEVER WOULD HAVE GUESSED THAT YOU'RE THE SHY TYPE!" Mettaton was hunched over from laughing so hard.
Sans and Toriel blushed.
"You're too cute, my boy" Gaster signed, finally managing to get a message across through his silent laughter.
"I really need to get my brain-to-mouth filter checked out" Sans muttered, remembering how he'd let so many secrets slip out because he couldn't keep his mouth shut.
"Well" Toriel giggled, "if it's any consolation, I nearly said yes before you fainted."
"Y-you did?" Sans squeaked, not noticing that his friends and family had stopped laughing to watch them, in fact, he'd forgotten all about them.
"Oh yes" Toriel nodded, "and I'm both thankful and disappointed for the fact that you fainted."
"Disappointed?" Sans repeated, half-knowing what her reply would be.
"Uh-huh" Toriel nodded, "if it weren't for your sudden lack of consciousness, you'd be my fiancee right now."
"W-well should I ask again then?" Sans winked, blushing furiously.
"How can I say no?" Toriel giggled, glad that Sans seemed mentally prepared this time.
"GET A ROOM!" Undyne shouted, reminding the couple that people were watching.
"We'll see" Sans grinned at Toriel.
"FORGET WHAT I SAID ABOUT SANS BEING SHY! HE'S A SMOOTH LITTLE FUCKER! I BET HE PLANNED THE ENTIRE THING!" Mettaton accused.
"That's for me to know and you to never find out" Sans smirked at the group before taking Toriel's hand and teleporting away.
"..." nobody said anything. They were too shocked.
"Does Sans ever give a straight answer?" Gaster signed to Papyrus.