Hello my friends, and welcome to my first story for the Undertale fandom, and indeed my first story in several years.
The fabulous author Sunfreckle who some of you may know as the author of the recently finished story Happy Family told me some time ago that I'd be good at writing songfics due to my love of music, so here goes nothing.

Disclaimer: Undertale belongs to Toby Fox and all songs mentioned herein belong to their respective owners. Also, Frisk is female in this so if any of you are put off by that turn back now.

Chapter one: You're Mine

It was around six in the evening when Frisk, Asriel, Chara, Sans and Toriel were at Grillby's enjoying a nice family dinner. Out of the corner of his eye socket Sans noticed something he had never seen in the establishment before, a Karaoke machine.
'Heh, should be good for a giggle' he thought to himself as he put down his burger and walked towards the machine. Noticing his actions Toriel called out to him "Sans, what is it you are doing?" Her brow arched curiously "Just sit back and relax Tori, your bone-friend here has a little something special planned." He said shooting her a wink "Very well then" she said giggling before continuing to eat her grilled chicken salad.

When he walked up to the machine Sans merely needed to enter his name and input his song selection before he grabbed a microphone and waited for the lyrics to appear on the screen in front of him.

As the song's intro drew to a close sans took a deep breath and prepared to sing 'here goes' he thought before he started singing.

"I've begun to realize that I'm better when I am with you, you deliver me from the pain in my life"

"Easy now to recognize all the misery I have been through, it was beating me to submission 'til the day you arrived"

"Certainly, I felt alive"

"Strength I had lost was revived, and mending inside and we both know why"

"'Cause you're mine!"

"I knew I could be whole if you were mine"

"I'll vanquish any foe because you're mine~"

"Been betrayed too many times, didn't think I would ever recover, it'd haunt me for the rest of my life"

"Then you opened up my eyes and you helped me rediscover, you're the one who resurrected a man who had died"

"Your power it gave me new life, made me reborn and refined"

"Rebuilt from inside, and we both know why..."

"'Cause you're mine!"

"I knew I could be whole if you were mine"

"I'll vanquish any foe because you're mine~"

At this point there was a brief musical interlude in which Chara turned to Toriel and said "wow, for a guy who doesn't have lungs Sans has a great set of pipes" before continuing to eat her half rack of ribs (which she ordered to bug sans)"He certainly does my child" said Toriel breathlessly as she stared transfixed at her boyfriend. She was snapped out of her reverie when she saw Asriel playing air guitar and Frisk chuckling at her brother's antics. However as Sans began to sing again they all fell silent and watched.

"I never thought I would ever escape, at times I wanted to die!"

"Feared that it all was just a little too late, thought that I wouldn't survive"

"I let you in and let go of the hate, my heart recovered now I owe you a debt that I can never repay"

As he sang these lines Sans' eyes were the empty black voids they were when he was in "serious" mode before regaining their usual light

"I still believe 'cause you're mine"

"I'm burning inside and we both know why"

"'Cause you're mine!"

"I knew I could be whole if you were..."

"mine~"

"I'll vanquish any foe because you're...

"mine~"

"I can regain control because you're..."

"mine~"

"I can take over the world because you're..."

"mine~"

"mine~"

As the music wound down Sans exited the stage to the applause of the restaurant's other patrons including his girlfriend and kids.
When he sat down he noticed that even though Toriel was smiling she had a tear in her eye "what's wrong Tori?" he asked with a slight hint of concern "oh Sans, that was beautiful." "Yea Sans, that was awesome!" Asriel all but shouted "Eh, it was alright" Chara said in her usual aloof fashion but it was obvious from her smirk she enjoyed the performance. "You rock dad, that was EPIC" Frisk shouted standing up to both fist bump her adopted father and also to let him sit back down.

"That was quite a show, I absolutely loved it dear" Toriel said before kissing the top of Sans' skull "aww, thanks Tori." he said, a light blue blush adorning his cheekbones "Glad ya liked it, I thought I'd have to SCALE it back. It took a moment for Sans' words to sink in before everyone was laughing at the joke.

As their laughter died down a comfortable silence had fallen over the family before Grillby had walked over to their table. "Would you care for some dessert, or coffee or anything like that?" Grillby asked. "Nah, we'll just take the check Grillbz." "Very well then" the fire elemental said in his usual crackling voice before going to fetch their bill for the evening.

"So mom, I've been giving it a bit of thought and I think I'm gonna go to the casting call for the local Halloween attraction they hold at the fairgrounds just outside of town." Chara said looking at Toriel "That is an interesting idea, my child and I think it is nice you wish to use some of your talents to entertain people."

"Yea, you should do your creepy melting black goo face when you go!" Asriel said excitedly which caused an excited (and somewhat evil looking) grin to spread across her face. "Azzy, that's an awesome idea!"
Chara all but shouted, enveloping her brother in a hug (which to him seemed more like a choke hold).

As she let go Grillby retuned with the check "Thanks Grillbz" Sans said taking the check folder and slipping some money in and giving it to the fire elemental. "keep the change" Sans said to his old friend.

Grillby then nodded in thanks and walked off to the back room.

"What a lovely evening; dinner and a show, thank you Sans." Toriel said giving him a kiss on the top of his skull "Yea thanks dad, that was great!" Frisk said giving Sans a hug.

The family then exited the restaurant and drove home where they eventually drifted off into a pleasant slumber.

Sans was awoken the next morning by his phone indicating he had just received a text, upon inspection he saw that it was from Alphys and it simply said "you're internet famous!" underneath the message was a link to a Youtube video showing Sans's performance the previous evening.
"Heh, the camera really does add ten pounds" Sans said before getting up and starting his day.

Hello, my friends! This is just an idea that popped into my head a while ago and I've slowly but surely been adding to it. I'm sorry if it sucks or it seems disjointed or it doesn't flow very well, I haven't written anything in ages so I'm a bit rusty. But enough self deprecation; this is Crow signing off.