Okay guys, compared to the first three, this is a looong chapter. But I couldn't really bring myself to split it into two parts and continue writing Frisk this angsty. I wanted there to be a happy end to this chapter so we can move on and get to other stuff. BTW, I'm not sure if the end of this chapter warrants a jump in the rating, since I suppose it's a little suggestive, but mostly kind of fluffy in a way. I mean, sexytimes are fun and all, but I myself am not game enough to write them! 0/0

I also know it's taken a while for this chapter to come out but it's Christmas time and life is busy and whatnot, so it might be a little while as well for chapter five, but rest assured! I have chapters planned and won't abandon this fic before it gets a proper outcome!

Either way, I hope you guys enjoy and stay Determined!

Sans tip-toed out of the bedroom door, trying not to wake Papyrus up, who was snoring quite loudly in the next room. Sans knew he needed to tread carefully with how he'd go about comforting Frisk, since she'd insisted all the times before when this happened that she'd be fine on her own. But this had been happening too many times now to ignore, and Sans was determined to at least to try and get her to open up about what was bothering her.

She may have always been a resilient person, but this needless bottling up of feelings simply wouldn't do. The poor girl had been through so much already and had so much pressure thrust upon her at a young age, it wasn't fair for her to have to go about all this on her own, Sans thought. He may not have always seen her in the light that he does now, a beautiful and spirited young woman, but the one thing that never changed was the fact that he was always looking out for her.

Frisk had feelings for Sans for quite a long time, and Sans reciprocated her romantic feelings after she turned eighteen. They now had been dating for about a year and a half, but their romantic relationship was something they kept mainly to themselves for various reasons.

For one, the last thing Frisk needed was the human press hounding her anymore than they already did, and she knew that their relationship would be made a total spectacle of, regardless if it was viewed by people in a positive or a negative light. Considering the fact that they assumed that Frisk had been taken prisoner by the monsters seven years ago, they might try to create some sort of scandal in which they spread rumours that she'd been "corrupted" by monsters or some other nonsense.

The monster world was diverse and accepting when it came to romantic relationships, but that wasn't so much the case among humans, they learned. When Undyne and Alphys finally settled in on the surface, they had a hard time believing that it was against the law in many places for two women to marry one another or adopt children, not to mention the burning questions they got pertaining to how their physical relationship would work between a fish woman and a lizard.

That was why Sans and Frisk also kept their relationship a secret from most of the monsters outside of their truest companions. One of the reasons at least. Someone was bound to run their mouth to the tabloids in return for a handsome reward. Frisk didn't even come out about her relationship to Toriel and Asgore. Not that they still treated her like a child or a naïve teen, (Well, at least Asgore didn't) but Toriel in particular shared a certain kinship with Sans, since they were both lovers of groan-inducing puns and practical jokes, and in her eyes, Sans was like an older brother to Frisk, and she had him promise all those years ago to always look out for her and protect her, so Frisk was a little worried of how she'd react if she were to tell her. She promised herself that she would tell both her parents at some point, but for now, she thought it was best to play it safe.

A few of the monsters in the village they lived in had picked up on them being together. But then again, most of them were people that Frisk could trust to keep a secret, or a half-secret at least, considering that a lot of the time, for as much as the couple wanted to keep their private life private, the human girl and skeleton guy didn't make much of an effort to hide their affection in public. Grillby always saw them snuggling together in a booth at his diner, the former Royal Guard dogs could smell each other's scent on the other, and even though they hadn't officially told Undyne and Alphys that they were a couple, Undyne always had to tease them about how cosy they were around each other. She'd already picked up on it, and no doubt informed Alphys in her own time.

Papyrus was fully aware of what was going on between them. Sort of. Frisk and Sans both agreed that they'd make no effort to try and hide it from him, considering that he was the former's brother and their housemate who slept in the room right across from them. There was no way that they could hide what was going on in that bedroom on some nights. Papyrus was innocent, but even he wasn't that naïve. So why even bother to hide it? Papyrus was happy for them anyway. Though sometimes a little too happy. ("YOU TWO ARE MY NUMBER ONE SHIP!") But he gave them their space when they needed it, and honestly didn't really question the "activities" that occurred behind closed doors. He probably assumed they were just solving an intense kind of puzzle. A very Papyrus thing to presume.

The other reason Frisk and Sans tried to keep their relationship as private as they could was the fact of the uncomfortable elephant in the room: Sans met and grew close to Frisk when she was a twelve year old girl, and when he was already a grown male. A fact that Frisk always tried to ignore, but couldn't deny. Sometimes she wondered if what they were doing was taboo, as even the monster world had standards on what was socially acceptable when it came to love and sex.

But she really didn't want herself or Sans to think about it that way, and at the end of the day, she was too happy with the way things were. The Skeleton species of monsters didn't actually age, as Sans informed Frisk a long time ago, but it still didn't make the fact any less questionable. Questionable at least to Sans, who frankly felt way more uneasy about the situation at times than his girlfriend did. Frisk was worried only if others perceived it as creepy, if only for the personal safety of the two, otherwise she couldn't care less what others thought.

Sans on the other hand, was worried if he himself was creepy, but Frisk assured him that he wasn't a creep. She'd playfully tease him by telling him that he was inherently creepy by being a skeleton, then do a suggestive wiggle of her hips or give him a deep kiss to fluster him some more. She loved doing that to him, and it was usually the way that discussion would end. All would be forgotten in a passionate kiss or tickle fight.

But tonight, Sans knew that they'd need to have a proper discussion on Frisk's late night trips downstairs after these nightmares, and he wouldn't take no for an answer. Sans had picked up on what might be going on in her head, and while he wasn't a mind reader, he knew a lot more about what not only was happening in the present, but what had happened in the past. Sans knew that it was time for him to own up to some things himself.

Frisk was fixing herself a snack in the kitchen, some easy instant noodles. Her eyes hurt from crying. She knew it was pointless, but when else would she be able to do it? Not that she wasn't an emotional person, but she refused to cry on camera and preferred not to cry in company if she could help it. She'd mostly broken down in tears of sorrow in front of Toriel and Asgore. They were her parents after all, and they wouldn't fault their little girl for being emotionally vulnerable. She'd cried in front of Sans before, but still had yet to allow herself to go to that dark place in her mind and let herself by vulnerable in front of him.

She sat back on the couch, digging into the noodles. A late night showing of music videos was on, but Frisk kept the volume down quite low. It's not like she was even listening anyway. The flashy colours were pretty though. It was the perfect brain rotting garbage.

Sans tip-toed down the stairs as quietly as he could, but allowed his footsteps to become heavier as he approached the living room, to make sure he didn't alarm Frisk. He stood at the back of the couch, trying to find the right words to break the silence. He walked round to the side of the couch. "Hey kid, whatcha doing out here so early in the morning?" Sans asked in a soft voice. Frisk turned her head slowly to face him. Great, he tracked her down, she thought. She didn't respond. She hung her head down. He knew damn well why she was out here. Sans sat down on the couch next to her. "Ya look bone tired. Another nightmare, right?"

Frisk sighed sadly. "You know me too well." She looked up at Sans. "I just wish I could get a proper night's rest." She was holding back a choke in her voice. Sans nodded at her with a tender expression. "You know you can talk to me, babe. You can't keep hiding these worries to yourself." Frisk took a deep breath and tried to keep her words steady. "I-I know but, it's not just about the dreams I'm having... w-well it is, but it's the dreams that have been bringing back bad memories that I've been too ashamed of to share with anyone." Frisk continued in a shaky voice, her heart pounding. "Sans... some of the things I've done... y-you'd never forgive me for." Tears began to well in the ducts of Frisk's eyes. Sans placed his right hand on Frisk's back and tenderly began to rub. "I thought I'd really have a hard time trying to convince you to talk to me about this." Sans whispered to her gently. "But babe, it looks like you're at the end of your tether."

And Sans was completely right. Frisk suddenly broke into sobs, head in her hands. But Sans encouraged her to look up at him and pulled her into a close, warm hug, her head nestled in on his shoulder blade, with him continuing to rub her back lovingly. "I'm sorry, I'm so sorry." Frisk whimpered through strangled sobs. "Shhh, baby girl," Sans whispered to her. "You have nothing to be sorry for, okay? Nothing."

Frisk looked up again at Sans, shaking her head. "But I do! There's so much I have to own up to! Stuff I should've told you about long ago." She sniffled. Sans had a hunch she was ready to talk about some times that she didn't know that he knew. "Stuff like what?" He asked her. Frisk took in a shaky breath. "W-Well... for a start... w-what if I told you, that all those years ago, and even now I suppose... I had the power to do s-some kind of do-over?" Frisk broke into sobs again. Sans saw that Frisk was getting distraught, and it hurt to see her like this. So he decided that this was the best time to tell her.

"Frisk, sweetheart. I know about the resets." Frisk looked up, and her eyes widened. That meant... did he already know of the mistakes she made? "Granted, I don't remember all the events that take place in each of them only pieces that I've had to relive multiple times, but I'm at least able to keep track of them. You do know that I'm kind of a quantum physicist, right? Sure, I'm long retired from that occupation, but you of all people know I'm not quite the bonehead that everyone thinks of me as." Sans chuckled.

Frisk was shocked, but as soon as Sans mentioned that he was in fact once a quantum physicist, a few things suddenly made sense. "How do you think I knew all the shortcuts? Not to mention that time you gained access to my workroom at the old home's back shed? Ay, remember that, girly? I really made you say "I'm the legendary fartmaster" to gain access to that place." That memory got a giggle out of Frisk. Sans grinned ear to non-existent ear at her smile. "Yeah, I do." Frisk said. She pulled away from Sans' embrace, remembering that he still didn't know of all the events that took place. "Sans..." Frisk took another deep breath. "Do you remember then that... in a few timelines, before resetting... I actually killed a few monsters by accident... in self-defence?" She couldn't quite look Sans in the eyes.

"Well... I can imagine that it happened for sure in a few timelines. But they were timelines you reset, right? Plus I know in my heart that they were accidents." Sans said to Frisk, placing her hands in his. "You can't do everything perfect the first time. Especially considering that looking back on it, you really were being attacked from every corner."

Frisk spoke up. "You're being too forgiving Sans. It wasn't something that just happened once." She had to tell him. "The first time, before I even reset the first timeline, I accidently..." Frisk started to cry again. "I killed Toriel." Sans' eyes widened. Frisk moved away from him. She was prepared for him to hate her. "And I obviously reset that too, trust me, I know I'm a horrible person for what I did, but she was coming at me with all her strength and I didn't know what to do and-" Frisk was desperately choking out her words though sobs, barely stopping to breathe. "-And I just pushed her back when she got too close a few times and I had no idea at the time how fragile monsters were compared to humans but even after that when monsters attacked me I didn't think my actions through and-"

Sans had to calm her down. He couldn't bear to see her in this state. He stood up and walked towards her, reaching out for her. "Frisk, please clam down. I know this is hard for you to finally come out and talk about with but you just need to take a deep breath and-" Frisk suddenly blurted it out. There was no good was she could come out with it. "I killed Papyrus once!" She took a few steps back, not daring to look up at Sans. She kept her eyes on her feet. "It was the same situation as Toriel. I was scared and I didn't know what to do. I pushed him back to stop him from running at me but... I forgot how I was strong against monsters."

"I immediately went back and changed fate. But it didn't change the fact the in one timeline somewhere, I actually killed your brother." Frisk took a few more steps back, prepared to bolt out the door and run. Like the coward I am, she thought. "I didn't take responsibility for my actions and I just backtracked instead. I've hidden this from you for so that I don't deserve forgiveness. I j-just...I"

Frisk suddenly felt warm arms around her. She was in the tightest embrace she'd ever been in. This was not what she expected. What was remarkable was that she could hear Sans... sniffling. "Frisk... I am so glad that you were finally able to talk about this. You don't have to bottle all this up ever again. I just want to see my girl happy again."

Frisk was confused, but she felt an elation in her chest at the fact that he was holding her after her confession, not abhorring her. He held her, rubbing her back again and gently swaying her side by side. "But... y-you don't hate me for killing Papyrus?" She questioned. Sans breathed in her ear, which to be honest, she found quite pleasurable. "I'd never hate you. What you did happened a long a time ago and you changed it. Papyrus is upstairs, safe and asleep. That's the reality. If you didn't take responsibility then you wouldn't have changed the outcome. I know in my heart that you'd never kill Papyrus or Toriel with any evil intent. You were given a gift Frisk, and you've used it for good. Not evil, unlike the imposter I fought over a few timelines." Sans paused. "Or that Satanic little weed." By the word "weed", Frisk knew Sans must've meant Flowey. But she didn't know who this imposter is. "Who's the imposter?" She asked. "I don't wanna talk about it tonight. I'll go deeper into it another time." Sans said quietly.

The couple stayed in each other tight embrace for a few moments. It felt peaceful, relaxing and like a weight had been lifted from Frisk's shoulders. Suddenly, Sans started chuckling quietly. Frisk noticed this, finding it odd, "Huh? Is there something funny?" She asked. "Oh heh, I just had a thought. It was very likely that Papyrus annoyed you so much with his puzzles and heroic speeches that it drove you to murder." Sans broke out into a fit of giggles. Frisk looked up, a little disdained. "Sans, that is not funny." She scolded him, but had to admit to herself that it was lovely to see his goofy grin. "Sorry, sorry." Sans breathed, wiping a tear. "Just a little black humour, y'know?"

Frisk smiled. "Yeah. I guess." She loosened herself from San's embrace and sat down on the couch again, Sans following her. They were hand in hand again. Frisk then realised there was something else she forgot to tell him, albeit much more relaxed now about telling him. Before she could open her mouth though, Sans pulled her in for a toothy kiss. It was sweet and deep, and ultimately caused Frisk to forget what she was going to say. After a moment, she pulled away. "I'm exhausted." She sighed. Sans raised a non-existent eyebrow. "Exhausted, ay? Looks like it time for the kiddo to go back to bed." He smiled. Frisk gave Sans a raised eyebrow of her own. "Yeah. This so-called "kiddo" is a grown lady who needs her beauty sleep."

The couple got up from the couch and headed to the stairs. Halfway up, Sans broke the silence. "Say." He looked at Frisk sheepishly. "You're not too tired, are ya cutie?" Frisk said nothing. A smirk formed on her lips, eyes lidded. Looking closely, she saw a glimpse of blue in Sans' left eye.

"I love monster magic." Frisk giggled airily, legs tangled in the ruffled blankets and sheets. "You always say that." Sans said with a smile, loving the sound of her laugh. Frisk smiled back. "Yeah, but it's so true." Frisk was basking in her afterglow, eyes closed, snuggled up to San's chest. As bony as it was, she didn't care. It was still comforting. Sans' left arm was draped around the curve of Frisk's back. Still rubbing her back up and down, he utterly enjoyed the feel of her bare human skin. The couple were lying together, and were pretty spent.

"If I wasn't so tired, I'd go for another round. Seriously Frisk, your skin feels so good." Sans squeezed one of Frisk's breasts. She blushed at this. It was so nice to feel desired for even the simplest things. And the best part about it was that she knew Sans was genuine. Outside of practical jokes and puns, there was no bullshit with this guy.

Sans leaned in to whisper in her ear. "Sometimes, I wish I had skin of my own. It'd make it feel better for you." Frisk shook her head. "That's sweet of you, but you know I like you just the way you are. Besides, that magic of yours can do some truly wonderful things." Sans chuckled. "Yeah. I'll never forget that look on your face when I first demonstrated it. You looked like all your Christmases came at once." He paused and gave a her naughty grin. "Pun intended." Frisk playfully smacked his side. "Hey now, that's enough out of you, you naughty Skeley-Bear." Sans looked at her with a curious grin. That was a new one.

"Skeley-Bear?" He asked. "Well, yeah. Haven't you ever thought that you looked like a big ol' cuddly teddy bear?" Sans gave a mock frown. "You're gonna ruin my thug reputation, missy." He gave Frisk a tap on her rear. She squeaked a little. "Oh yeah, a thug that wears pink bunny slippers." She laughed. "Uh, yeah. Only a real thug wears bunny slippers." Sans said proudly.

Frisk squeezed Sans a little tighter in her arms. "Nah, you're a teddy bear and you know it. I never thought a skeleton could be so cuddly." "And passionate?" Sans added. "Yeah. That really surprised me." Frisk said. "But at the same time it didn't. You know what they say: The quiet ones are always the freaks." Sans laughed. "Speak for yourself, you little minx." He spanked her again. She squealed. "See? You like it when I punish ya." Sans looked at her with a cocky grin, that blue glint in his eye shining again.

Frisk looked straight in his eye, climbed on top of him, and the two indulged in a delicious kiss. Sans held her tight in his arms, and Frisk moaned in between parting breaths. She knew that would rile him up. "You saucy little minx." He breathed. "What are you trying to do to me?" Frisk stopped the kiss for a moment a looked at him with the most innocent eyes she could muster. "I dunno." She muttered almost silently.

They smiled at each other, And began to kiss again, Frisk moaning and earning approving grunts from Sans, as they engaged in their afterplay.

Sans' kiss and warm embrace filled Frisk with Determination.