You was sleeping soundly, when suddenly you hear a loud noise.

*Gaster Blaster :KaBoom!

"Ahh!" Surprised, you fell out of the bed and landed on the floor. You quickly scrambled to get up and ran to the door and opened it "What the heck?!" A few doors down from yours, you see Papyrus, Frisk, and Temmie, standing in shock and awe at what used to be San's room. You cautiously walked over, and peeked inside. You see Sans sitting up from his bed, staring in a trance, breathing heavily with his left eye glowing fiercely out of control.

You called out to him "Sans?..."

He quickly snaps out of it and calms down. He sees you all staring at him, concerned. He smiles not having a clue what's going on "Hey...why are you all staring at me like that?" He looks around to see that the door had been blown to bits, then realized what happened and blushes a deep blue shade. He covers his face, embarrassed "Oh no..." You tried to approach him, but he quickly jumps out of the bed and scrambles to the corner "Don't come any closer!" He opens a portal.

"Sans! Wait!"

You tried to call out to stop him, but he jumps through it. You looked at where he disappeared, then turned to look at Papyrus, worried " What happened?!"

He was still standing in shock, but snaps out of it when he heard you "I-I DON'T KNOW?! I THINK HE LOST CONTROL OF HIS MAGIC!"

You looked at him confused "But I thought he managed to control it?"

He wrings his hands nervously "It can sometimes be a bit unstable... if he's under a lot of stress or when there's something bothering him."

Then he grabs his head in full panic mode "OHH! WHERE COULD HE HAVE GONE?!"

You walked over to him and tried calm him down "I'll go and find him. Can you and the others wait here, in case he comes back?"

"OF COURSE, HUMAN! PLEASE FIND MY BROTHER!"

Gaster informs you ...Go to Grillby's...he usually goes there to skulk...

Sans sat at the bar seat staring off into space (...Man, what is wrong with me? I can't believe I lost control of my magic!...Every time I think or even see (Y/N) ,my heart feels funny...Could it be that I'm in love with her?)...Then he shakes his head then put his hand on it (...No...I can't, she's an human and I'm an monster...It would never work out...)

He hears a voice called out to him "Sans..."

He snaps out of his thoughts to see Grillby looking at him concerned. "Sans, you alright?"

He smiles nervously and rubs his head "Yeah! Of course, why wouldn't I be?..."

Grillby points to the untouched ketchup bottle in front of him "You didn't drink your ketchup...usually you would have drunk all of my supplies by now."

Sans smiled sheepishly "Oh yeah..."

"and you usually tell jokes non-stop."

He laughs half-heartedly "Ha Heh...i guess I've gone bone dried of jokes.~"

"Is it that human..."

He quickly looks at Grillby then said nothing for a while, Grillby takes his silence as a yes, until he sees you came in through the door. Grillby leans closer to him and whispers "You should tell her."

He sighs and played with his ketchup bottle, not answering him. Grillby sees you starting to walk towards them.

"She's coming over here right now. You better do something."

He begins to panic, but tries to cover it up when you got closer to him. He turns around and winks "Heh...Hey, ! I guess you caught me red handed.~ Ha, ha...we need to talk..."

You put your hands on your hips "I can say we do! What were you thinking taking off like that?! You had me, Papyrus and the others worried sick!"

He gets up from his seat "Come on I'll take you somewhere where we can talk, privately."

About halfway to the door he stops "Oh...and Grillby...put it on my tab!~"

You and Sans teleported back to the MTT Resort. You was going to open the door until he stops you "Not that way...Well go through the shortcut follow me."

He leads you to the side of the building and holds out a hand. You took it and the both of you went through the portal and ended up in the hotel's restaurant. You both took a seat and he clasps his hands. You could sense the serious atmosphere around him, then he looks at you straight in the eyes.

"Well here we are. So, the journey is almost over, huh? Maybe sometimes it's better to take what's given to you. Down here you already got food, drink, and friends...Is what you and Frisk have to do, really worth it?"

You looked at him, concerned "You sound like your giving up?..."

He looks down for a minute then smiles and shrugs it off and winks "Ah forget it. I'm rooting for you two.~ You probably heard me say this many times, y'know that I'm a sentry in Snowdin forest, right? I sit out there and watch for humans. It's kind of boring. Fortunately, deep in the forest...there's this huge locked door, and its perfect for practicing knock knock jokes.

So one day, I'm knocking em' out like usual, I knock on the door and say "knock knock", and suddenly from the other side I hear a woman's voice, "Who's there?." So naturally I respond:

"Dishes."

"Dishes who?."

"Dishes a very bad joke."

Then she just howls with laughter. Like it was the best joke she's heard in a hundred years. So I keep em' coming, and she keeps laughing. She's is the best audience I have ever had. Then, after about a dozen of em', she knocks and says...

"Knock knock!"

I said, "Who's there?"

"Old lady!"

"Old lady who?"

"Oh! I didn't know you could yodel!"

"Wow, needless to say this woman was extremely good. We kept telling each other jokes for hours. Eventually, I had to leave. Papyrus gets kind of cranky without his bed time story. But, she told me to come again, so I did. Then, again, and again. It's a thing now, telling bad jokes through the door, it rules. One day, though, I noticed that she wasn't laughing very much. I asked her what's up, she told me something very strange.

If a human ever comes through this door,...could you please, please promise me something? Watch over them, protect them, will you not?"

"Now, you know I hate making promises, and this woman, I didn't even know her name. But...someone who sincerely likes bad jokes...has an integrity you can't say "no" to."

He takes in a deep breath "Do you get what I'm saying? That promise I made to her...buddy..."

He turns and looks away from you so you couldn't see his face "You know what would have happened if she hadn't said anything?"

He quickly turns to look at you with his eye ferociously glowing blue, menacingly "...You two would have been dead from where you stand..."

You just sat there staring at him, unafraid. He gives you a scary grin "This is the part where you should be screaming and running away in fear, yelling "Monster!"

You looked down so he wouldn't see your face "Knock knock..."

He looks at you shocked for a minute then raises his eye, curious "Who's there?"

"Olive..."

"Olive who?"

You quickly looked up at him and gave a small smile "I love you, Sans~..."

His eyes widen in shock and he falls out of his seat "W-what?!"

"You heard me..."

He gets up and looks at you puzzled "Are you evening listening to yourself?! Do you even know what you're getting into?! I'm a vicious monster! You should be running away from me, with freight!"

You smiled "What's gotten your bones rattled?~"

He looks at you for a minute and silently laughs "I think it's time I told you the full story about what really happened 421 years ago..."

"421 years ago?"

"When the war broke out...my dad, Papyrus, and me barely managed to escape with our lives and managed to make it to . But I was injured..."

"Is that why your eye only glows on your left?..."

"Yes...We were some of the lucky ones, while some weren't, which caused some of monsters to grow anger towards humans. Before the barrier was casted I heard what some of the humans said:

"Serves them right!"

"Monsters is what they are!"

"They've deserve this for what they've done!"

After a while, it was peaceful, until some years later.

..several humans fell into the mountain...

(...Chara and The six souls!...)

...those monsters, the ones who were filled with hatred, killed them. Three, of whom you've already met..."

You answered, curiously "Who?..."

"Undyne, Muffet,...and me..."

You stared at him shocked, but stayed silent. He looks away, nervously "Hey don't get me wrong...back then I was going through some troubling stuff, it was until I met you and Frisk my world completely changed, because of your love and friendship...I see now that humans aren't what they made out to be. But, there is something I must warn you about...down here there is a gang of monsters who don't take too kindly towards humans. Which I have a feeling you will encounter soon..."

He looks away from you "I'll understand if you just walked away right now, after everything I've done...I'd wouldn't blame you... "

You smiled at him "So, how old are you Sans?"

He looks at you, shocked, then grins "125."

You gave him an teasing look "So, you're an old bag of bones!~"

He laughs at your joke "Heh..." then gets up and winks urging you to follow "Come on, Papyrus is probably screaming his head off wondering where we are."

When the two of you get to the exit, you stopped "Sans..."

He turns to look at you "Yeah?..."

You leaned down and kissed him on his teeth. His whole face turns blue and starts stammering while covering his face with his hood.

You hear him murmured something "Hmmm...ov...u..."

You smiled at him and pretend that you couldn't hear what he said "Sorry what was that? I didn't catch it..."

He peeks out of his hood so you could see him "Knock Knock..."

"Who's there?..."

"Olive..."

"Olive who?..."

"I love you too, ..."