That day, the monsters broke to the surface. It felt so strange, to feel the sun and the wind on their skin… Or whatever they had instead of skin.

Frisk was there, together with Toriel, Undyne, Alphys, everyone. Everyone was happy and alive, everything was fine.

Sans knew that someone was missing, but it couldn't be helped. Asriel couldn't come with them, not without a soul, not after all he had done since his death.

Frisk knew it too. They held Toriel's hand, but sometimes they glanced towards the tunnel that lead everyone to the surface.

Sans left Papyrus' side and reached Frisk, touching gently one shoulder of the little human. They lifted the head a little bit, and the tiny eyes of the human crossed the skeleton's eyesockets.

"Ya did well, kiddo"

No puns, no grins. Just that hand on the shoulder, and oh boy, that hand seemed heavy like a sin. Frisk replied with the slightest nod, and took Sans' bony hand with their smaller one.

"It's over now" he added, looking at the sunset in front of them.

After a few more seconds of awe, Asgore started talking about their future, what they were going to do, Frisk's role… Lot of things that the human didn't really listened to. They kept holding Sans' and Toriel's hands, breathing slowly.

It was over, yes. It was really over.

Many years have passed since that day. Everybody grew up, both mentally and physically, and of course, the one with the greatest changes was Frisk, since they were only a small child when they fell into the Underworld. They took the ambassador role really seriously, and grew up in a beautiful and strong human with a fierce smile and the head always up and ready to think of a way to ensure their friends' safety and wellbeing.

At least, that was how everybody saw them. Papyrus ranted about his best ambassador friend at least once a day, and Undyne obliged Frisk to train with her every time she had the chance. Alphys secretly wrote fanfictions about Frisk, where they held enormous anime-style weapons and fought valiantly, saving the world once again. Needless to say, Toriel was the proudest mom all of the proud moms… And yes, she and Asgore went back together, opened the first interracial school and lived happily, teaching history to humans and monsters, so that those tragedies would never happen again.

And then, there was Sans.

Their relationship had always been a bit deeper, a bit darker than the others. Papyrus, Undyne, they lived their life happily and fully, without a care in the world except what was right. Alphys lived for her girlfriend, her work and her anime. With them, Frisk always had something to talk about, some jokes or funny things to do.

With Sans, instead, Frisk could stay silent for hours and be okay. The skeleton kept sprouting terrible jokes with everyone, but with Frisk he seemed to be a little less comic, and a bit more… Sans.

No one noticed these details, because when they were with the others both the human and the skeleton managed to act extremely normal. For them, at least.

"Sans?"

"Mh?"

"Do you like me?"

It was a pacific evening. They were home alone, since Papyrus went to a cooking class with Undyne. Toriel went too, probably in order to stop them from accidentally killing the teacher with their enthusiasm.

"What kind of question is it, kiddo?"

"Do you like me?"

"Why are you asking?"

The skeleton's eyesockets tried to read the human's expression. They seemed… Determined.

"You know Monster Kid, right?"

"Yeah..."

"You know that he's always tripping, right?"

"Yeah..."

"Well, today he tripped on me."

Sans' expression became a little worried.

"Are you injured?" Monster Kid used to be a nice little fellow, but ten years on the surface made him a dinosaur-shaped guy of almost two meters. Who tripped an awful lot of times.

"No. I think he did that on purpose or something… Because when he was on top on me he told me that he likes me."

If skeletons had eyebrows, Sans' ones would have been well raised.

"And then? What did you say?"

"I said that I liked him too..." The human looked confused, unsure. "But then he… You know..." Frisk turned their eyes away. "He smiled and kissed me, and… I realized that he misunderstood me."

Sans chuckled softly. "Or maybe you misunderstood him."

"Yeah, maybe..."

"Ok, I'm sorry for the kid, but I still don't get it."

Frisk moved closer to Sans. They were on the couch, and no one was paying attention to the TV program they were watching before.

"I didn't want to be misunderstood by you too. So I wanted to ask you if you like me."

There it was again, that Determination. Sans felt a bit uneasy, and diverted his eyesockets towards the golden flowers' poster on the wall.

"Yes, I like you, Frisk."

"Like I like you, or like I like Monster Kid?"

That was a tricky one. Sans turned his skull facing Frisk once again, perplexed.

"And how do you like me?" asked, out of curiosity mixed with several other feelings.

"Like this."

Undyne's training made Frisk very quick and strong. They leaned over, grabbed Sans' skull and kissed him on the upper teeth.

"Ah. I get it now."

The skeleton didn't move a bone, and if he had lungs he probably would have stopped breathing for some seconds.

"So?" Frisk insisted, with a hopeful but a bit fearful smile. They were still close to Sans, that lifted one hand to gently brush the human's hair.

"Yes, I like you, Frisk."

"Like that?"

"Like that."

Frisk smiled brightly, but only for a second. Sans' voice seemed… Sad.

"And you're not happy with it?"

"Mh-mh"

Frisk didn't understand. They kissed the skeleton again, and this time they thought to have seen a small flickering blue light somewhere inside the skull.

"What's wrong?"

"Why do you like me?" asked the skeleton, serious down to the marrow.

"I..." They hesitated. "I like you. Isn't it enough?"

"Frisk" He always called them by their name when the topic was important. "I don't want to be your toy. Your way to relieve some stress or whatsoever."

The human's eyes grew wide, but they didn't reply, and let Sans continue.

"I'm too old for this stuff. I lived too many years, and saw too many things."

He sounded extremely lonely while saying so, but kept caressing Frisk's head.

"Alphys and Undyne are happy together..." tried to say the human, and the skeleton nodded.

"Yes. But I'm not Undyne and you're not Alphys. Thank goodness, or I would have had to watch those awful cartoons where everyone screams before attacking."

Despite that, the air was still heavy with tension. Seeing that Sans was determined to reject them in order not to suffer, filled Frisk with determination.

"So?" They kissed him again before he could reply. "Do you want me to stop doing this?"

The skeleton's hands shivered on Frisk's shirt. They understood that he didn't know what to choose.

"I would never hurt you" whispered on his non-existent lips.

"I know."

"Not again."

Frisk immediately regretted what they said. They looked Sans in the eyes with terror, but the skeleton smiled with a bit of melancholy. It was hard to tell, on a face without muscles or skin.

"I know."

Frisk's body grew up a lot in those years. They were almost taller than Sans, and surely heavier, but in that moment the skeleton pulled Frisk closer and lay down on the couch apparently without suffering from the weight on his chest.

"So?" asked the human again, brushing their fingers on Sans' bare arms. He did the same, and while the human moved their hands towards the hipbones, they asked "Do you want me to stop?"

He clenched his teeth, breathing heavily a couple of times. Then, a flash of blue sparkled both in his eye and around his hand.

Frisk found themselves floating in the air, but didn't pose any resistance. They were just… Curious.

Then, when Sans' magic moved their clothes, lifting their shirt and making their pants fall on the floor, curiosity left place to something different.

"Do YOU want me to stop, kiddo?"

Sans' voice was rougher than usual. Excited, one could have said. He looked at Frisk's naked body and realized that he didn't know if those attributes where masculine or feminine. He also realized that he didn't care, especially when the human was looking at him with those eyes.

"No" they whispered, with a slight movement of the head.

"I could hurt you" warned the skeleton, and pointed to his mouth. "Skeletons don't give sweet kisses like yours."

Frisk bit their lower lip, trembling with anticipation. "And what do they do?"

"They bite, kiddo."

"Do you want to bite me?"

That fake innocent voice, those eyes lusting with desire… Sans' logic sense was struggling to be heard. And losing.

He couldn't do it. Frisk was too young. Too human, too fragile. He just couldn't.

"Yes."

He couldn't. He shouldn't.

He didn't want to get hurt, to suffer. Not again.

"Do it, then."

And he didn't want to hurt Frisk. No, that was a lie. There was a part of him that actually wanted to see the human suffer, and that was something that scared the skin out of him. It didn't matter that he didn't have one.

"Kids like you..." exhaled the skeleton, making the human float closer to him. "Should be punished, you know?"

He didn't mean to sound serious, but for a moment Frisk's eyes scared him. They were literally begging for punishment.

"Do it" whimpered, so softly that Sans almost didn't hear it. The skeleton pulled them into his arms and held them tightly.

"No" he murmured "I'll do something better."

He will be burning in hell, one day. But for now, the only thing that was burning was desire.

Sans didn't joke: skeletons do really bite. Frisk's body got covered of red marks pretty soon, but each time Sans bit them, they moaned and held him tighter. They liked it, and their pleasure was having a really weird effect on the skeleton.

He knew stuff about sex, of course, but since the… Lack of meat, we could say, he really didn't try to enjoy the act. Nothing to put anywhere, nothing where someone could seriously put something. Accepting that, he was prepared to exclusively pleasure Frisk, and be content with that.

He bit and touched, scratched and held that fleshy and warm body that reacted so juicily every time he did something. He touched Frisk between their thighs, and the human helped him showing how to do it properly. When Sans got it, Frisk's moans grew in intensity and frequency.

Sans was enjoying it, way more than he had expected. He felt excited, and every time Frisk sighed or moaned, he found himself doing the same.

The human opened the eyes, and for a moment they were scared.

"Sans" called him with a panting voice "What are those?"

The skeleton turned the skull and saw his Gaster Blasters behind him. There was something different from the ones he used to fight… There looked happy, in a certain way. Not blue, but with a tiny shade of red.

"They're enjoying the show" grinned, turning back to Frisk "And I'd say it's time for a good boning."

"Did you just make a-AHN!"

Sans' movement intensified, and so the pleasure. He didn't know why, but he shared what Frisk was feeling in that moment. Maybe it was magic, but he didn't bother to find an explanation, he had better things to do.

He bit their neck and moved faster with his hands, while Frisk grabbed his collarbones and panted against his teeth.

Finally, the human came with a loud scream, and less than one second after, those weird Gaster Blasters let out a powerful white ray that hit both Sans and Frisk, without actually doing it. It was like liquid light, and it vanished without a trace just few moments later.

"Are you okay?" the human asked after some minutes in which they just lay close, holding hands and catching their breath.

"Mh-mh" Sans was staring at the ceiling. "And ya?"

"I feel a bitten."

They grinned, and the skeleton snorted a quiet laugh. That pun was terrible, but actually, all those marks on Frisk's body couldn't be ignored easily.

"I want to ask ya something."

Frisk felt that something serious was coming. They straightened themselves up on one elbow, and nodded.

"Okay. Go ahead."

"Why did you do it?"

"Well… Because I like you and I wanted to sl-"

"Not that."

Sans turned his eyes toward Frisk. He was deadly serious, but also kinda relaxed.

"Why did you kill us all, the first time?"

Oh, no. Not that question. Frisk was prepared for everything else, but not that question. They lowered their eyes and bit their lower lips.

"So… It's true, then" replied with a trembling voice. "You really remember. Even after the resets."

Sans stroked gently the human's hair.

"Yes. But don't worry, I'm the only one."

"Why?"

He shrugged. "Beats me." He rolled on one side, to have Frisk's face in front of his eyesockets.

"So? Can you answer me?" asked again, gently, with his hand resting on Frisk's hip.

"I..." He was already on the verge of crying. "I was afraid of Toriel."

Normally Sans would have laughed, but that was not a normal moment.

"Why? She treated you gently, I think. She always does."

"Yes. Too gently. Too sweetly" nodded the human "I found lot of kids' shoes in a room, and I thought… I thought..." Their voice was breaking. "I thought that she wanted to keep me with her forever, like a… Sadistic mother-child relationship! I couldn't believe that someone could really be so… Nice."

They sniffed, and Sans kept his motionless face right in front of Frisk's.

"Okay, and then? After Toriel, why did you have to kill everyone?"

"I heard… A voice… A voice in my head… Telling me to do it, and..." Frisk was sobbing, but Sans didn't lift a finger to comfort them. "And I did it! I did it and… I felt so horrible… But I couldn't help it… I couldn't come back..."

Merciless Sans didn't think of sparing them.

"You killed Papyrus."

"Y-yes..."

"You killed my brother, who was opening his arms and offering you his friendship."

Sans' ice-cold voice make Frisk cry in pain.

"And you killed me too."

The human could only nod with a muffed scream of pain, their face hidden under their hands. The skeleton took them with gentle strength and forced the human to look at him. They looked so fragile, so vulnerable… Sans had to force himself to cast away the image of those sorry eyes red with anger and folly, grinning at him.

"But then, you reset. Right?"

The human nodded again, sniffing a couple of times. They knew that Sans wanted to reach a point in his speech.

"You reset and you managed to make everyone happy. You freed us, you helped us, you made this world a better place."

He gently touched their cheek, wet with tears.

"S-so… Do you f-forgive me?"

The skeleton shook his head, but kept smiling.

"No, kiddo. I will never forgive you for what you did." Frisk's world collapsed under the weight of those calm words. "But… That doesn't mean that I cannot… Like you all the same."

They stared at each other for some moments, trying to understand what that sentence could imply. For both.

"What do you mean? Don't you hate me?" It was funny, since he just told them the opposite. But tears still lingered at the corners of their eyes, and heart and soul pounded like war drums.

"I killed you so many times that I stopped hating you" was the melancholic reply. He brushed his fingers through their hair once again. "And I saw your efforts to redeem yourself. I believe…" He smiled with a bit more warmth in his bones. "That being born good is okay. But overcoming one's own nature, and BECOMING good is way more valuable."

He pulled Frisk closer and gave them a little bite on the cheek. Skeletons don't kiss.

The human buried their face in Sans' shirt and sobbed faintly.

"Thank you" Their voice was cracked: joy, relief, regret, pain, all these emotions couldn't let the human stop crying. "Thank you, Sans."

"It's okay, kiddo. It's over. Remember?"

Frisk nodded, and sniffed a bit harder.

"It was already over when we got to the surface."

He kept the human close to him, and felt their tiny but powerful heart pounding strongly for some more seconds, before calming down to a more relaxed pace.

"Sans"

"Mh?"

"I like you so much"

The skeleton smiled. They could never use again the word "love". Even without capitals letters.

But still, the skeleton smiled and bashed himself in the light of that thought.

"Me too, kid."

"I'm not a kid anymore, you know?" they replied with a grin, and leaned over to kiss him again. Even without lips, he realized he enjoyed it.

When the skeleton cackled, Frisk frowned. "What did I say now?"

"Oh, nothing" he kept snorting at his own not-yet-made joke. "It's just…"

He looked at them with that anticipation that could only announce some terrible pun. Frisk sighed and prepared themselves to the worst.

"How do you know when skeletons want to have sex?"

"...I don't... Knooow?"

He chuckled again and pulled Frisk on top of him.

"They have a boner."