The father figure
"U-ummm...G-gaster..? Are y-you ok??" Alphys asked as she saw the old skeleton hiding in the bushes. The man jumped, being startled by the young girl.
"A-Ah! Alphys! I see you are doing good today! How may i help??" Alphys looked at the man with an unphased expression.
"Y-you are s-sitting in the bushes....S-spying on F-Frisk a-and S-Sans..." Gaster cleared his throat, clearly caught.
"W-what makes you think I am spying on them?? I'm merely studying this bush." Alphys face-palmed.
"L-Look! Sans i-is h-hugging F-Frisk!!" Alphys said, pretending to be surprised. The two were just looking at Sans phone.
"Where?!" Gaster said looking in their direction. Alphys crossed her arms at the old man. He sighed.
"Fine... I just want my boy to not do a wrong thing with my little girl that's not really my little girl." Alphys face-palmed as Gaster's eye-lights bore into the two.
"Do you feel...like someone's watching us?" Frisk said shuddering. Sans shuddered as well.
"i do too..the heck??" They both started looking around and Gaster ducked in the bushes. Sans sockets went blank as he spotted his father. Frisk didn't see him.
"Uhhh...Sans..?" Sans smirked. His old man was spying on them huh? Might as well make it worth it.
"hey frisk? knock knock." Frisk crossed her hands.
"Who's there?"
"kiss." Frisk face-palmed and giggled.
"Kiss who?"
"me, duh. i'm your boyfriend." Frisk rolled her eyes and gave him a kiss on the cheek-bone. Gaster shot up from the bushes and was looking at Sans with rage. Sans smirked and winked at him. The scientist was fuming at this point. He grabbed her waist and started leading her inside the school. Before they entered he made a gesture of tipping his hat at the man. Alphys chuckled.
"HE JUST TOUCHED HER LIKE THAT?! OHHH! HE'S ON!!" Alphys sighed. This will be interesting to watch.
"KIDS! I'M DOING LAUNDRY!!" Gaster said. Papyrus came downstairs, bringing his dirty clothes, but the other two trouble-makers were nowhere to be seen. Gaster grabbed the bridge above his nasal cavity and called them again.
"KIDS!!...Frisk? Sans??" He said as he went over to Sans bedroom. Silence. He went over to Frisk's and heard voices. He was about to open the door when--
"Ok ok i get it now let go of my hair.....Holy shit! It's huge!!" Gaster froze dead in his tracks. Huge..? Hair...? Hold on...they couldn't be talking about-- THEY'RE JUST 13!!
"i guess...WHAT THE HELL DON'T STROKE IT LIKE THAT! I-IT TICKLES!" Gaster backed away from the door in shock...His little girl was being touched and manipulated and his son was taking advantage of-- He immediately kicked it open.
"DON'T YOU DARE SANS TO--....uhhh... He found the two kids on the bed staring at Sans scar from his arm from an acid burn that he got helping him. Sans and Frisk stared confused.
"uhh...to what...?" Gaster blinked a few times as Frisk tilted her head and then froze, blushing bright red.
"WHAT THE FUCK GASTER!! WE'RE 13!!" Sans tilted his head as well then his sockets went blank.
"OH MY GOD! WERE YOU LISTENING THE WHOLE TIME?! GET OUT!!" Sans and Frisk threw their pillows towards the man who just entered the room and he immediately closed it. Ohhh boy...The two kids stared at each other in disbelief.
"never speak of this again?"
"Agreed..." Frisk said as they did their salute. Frisk buried her face in the sheets and Sans pulled his hood over his face. That man was dead for both of them.
"Gaster...can you let me go..? we're late for the movies..." Frisk said. Gaster hugged her tighter. Frisk gasped. Sans frowned.
"HE IS TAKING MY BABY GIRL AWAY!!" Sans pulled Frisk towards him.
"dad, you're squishing her...and she isn't your daughter..." Gaster frowned.
"If you won't bring her back by 8 this time i will take your phalanges and stir my tea with them."
"I'M YOUR SON?!" Sans asked in disbelief as Gaster was staring him down.
"STILL NOT FIT ENOUGH TO DAT HER!!" Sans shrugged.
"too bad. cya, old man." He said with a wink as he pulled Frisk closer by her waist and she blushed. He saluted with two fingers and teleported away.
"SANS GILBER GASTER YOU DO NOT TOUCH HER LIKE THAT!! AGHHH!!" Gaster said stomping his foot. Fine, if his son will play dirty, he will as well.
"G-Gaster..i-i get t-that you are w-worried f-for F-Frisk a-and y-you're overprotective...B-but why a-am i h-here." Gaster nodded in understanding.
"I haven't seen romance in years. You know better. You are here to tell me when something feels...what do you call it? 'spicy'?" Alphys looked at the man and gestured at them.
"W-WHY A-ARE W-WE I-IN A TREE L-LOOKING IN THE CINEMA R-ROOM!!" Gaster scoffed.
"Because they would know if we were in. I am not good with disguises." Alphys face-palmed.
"N-not g-good with s-spying e-either.." Gaster frowned.
"You get to do 3 experiments more this week." Alphys lit up.
"S-spying it i-is!!" She took the binoculars and started watching the two in the cinema room.
Sans and Frisk were watching a monster and human movie again.
"Bro, i don't look that desperate right?" Frisk asked as she threw some pop-corn up and caught it in her mouth. Sans had an arm around her shoulder.
"to be honest, if it weren't the fact i'm on a date with you? i would already be asleep." Frisk started laughing.
"Oh come on...Look! She's about to get killed by the big bad monster." Sans scrunched his face up.
"why do humans assume skeleton's have scythes..?" Frisk snorted.
"Oh noooo...The Grim Reaper will kill meee oh nooo~" Frisk said wiggling her arms. Sans frowned.
"that's it! get here!!" Sans got on top of Frisk by stretching on her chair and started tickling her.
"O-oh my g-god!" Alphys said as she put down the binoculars.
"WHAT?!" Gaster asked.
"H-He's now o-on t-top o-of h-her..." Alphys said, blushing a bit as she remembered she wrote fanfiction about this.
"NOT MY BABY GIRL!!" Gaster said as he pulled the binoculars. Alphys looked at the man in confusion.
"Y-you're n-not her f-father--"
"OH MY GOD!! THEY ARE MAKING OUT AREN'T THEY?? HE'S TOTALLY FORCING HER! HANDS OFF MY BABY GIRL!!" Alphys face-palmed.
"ah shi--" Sans said as something pulled him by his hood and he fell off his chair. Frisk panted for air and looked at the skeleton on the floor.
"You ok there??" He gave her a thumbs up.
"yeah i'm--.....fine..." He said as the popcorn bucket fell on his head. Frisk snorted and started laughing at him.
"oh come on...i actually payed for those." Frisk's eyes widened as she looked down and saw the Tabby cat working there coming for them.
"That's Tobias dad!! Get up you idiot!" Sans raised a bone-brow.
"tobias..?" Frisk sighed.
"Burgerpants you idiot.." Sans shot up like burnt and gathered all the mess using his blue magic and he threw it in the trash-can. He put an arm around her shoulder. The cat eyed them suspiciously. They smiled. He scoffed and left.
"HE'S STILL TOUCHING HER!!" Alphys face-palmed.
"I-It's a d-date Mr. G..T-they a-are s-supposed to do t-that." Gaster frowned.
"I refuse!!" He used his purple magic and suddenly Sans hand was off her shoulder. Sans recognized the magic.
"frisk..? how much till the movie ends..?" Frisk looked at her phone.
"Around 5 minutes don't worry..." Sans frowned.
"the old man has been spying on us this whole time, no doubt." Frisk snorted and started giggling.
"oh shut up! i'm dead meat when i get home!" Frisk rolled her eyes.
"Yeah, well watch it the lights are turning back on." Sans froze as she kissed him on the teeth as she got up. He was blue now.
"YES!" Alphys said.
"NO!" Gaster yelled. Sans chuckled and teleported after Frisk.
"THIS IOS A DISASTER!! SHE JUST KISSED A BOY!" Alphys face-palmed.
"T-that's your son--"
"NOT GOOD ENOUGH!!" Alphys scoffed. The two came out from the cinema.
"S A N S . . ." The older skeleton brother heard as his father was standing in front of the door. He immediately took his hands off of Frisk and she stiffened.
"G~ wassup?" Frisk said awkwardly as she put herself between the mad older skeleton and her skeleton.
"YOUUUU--" Sans gulped.
"CYA!" He said as he teleported to his room. Frisk face-palmed and started walking towards her room.
"What a party pooper..." Frisk said as she closed the door. Gaster smiled in triumph.
"Hands off of her Sans." Gaster said, glaring at his son who was sitting with a napping Frisk in his arms. He shot his father a glare back.
"excuse you, if you wake her up, you're dead." Gaster frowned.
"No touching. You aren't allowed in a 2 feet radius from her!!" Papyrus came down the stairs.
"NYEAH HEH HEH!! BROTHER YOU LOOK SO CUTE TOGETHER!!" Sans blushed. Gaster pointed his spatula at Papyrus.
"Don't encourage them!!" Gaster said frowning.
"Let him encourage us, he's got the back-bone to do it." Frisk said opening one eye, lazily. Sans snorted. Papyrus groaned.
"STOP IT...PLEASE..." Sans smirked.
"yeah, you need more guts to do it." Frisk snorted. Gaster hit his head with the spatula and backed away in the kitchen.
"I am watching you two...HMMM..." Frisk and Sans looked at each other.
"wanna kiss in front of him and anger him?"
"Heh. You're a dead man." Sans shrugged.
"i'm already one foot in the grave." Frisk rolled her eyes as they got off to anger the older skeleton.
That day everyone learned a valuable lesson: Do not let Sans touch Frisk if YOU are in a 2 feet radius from Gaster... you might just end up a picture on a wall or a carpet on the floor just like him.