Sans is a MONSTER and not a HUMAN, so he doesn't follow HUMAN biology like a HUMAN skeleton. Same with Gaster and Papyrus.   

---------------------------------------

"Why do you always let Chara win?" Blair grumbled in frustration, as she glared at Asriel from across the table they were sitting at. The fox, Andrew, Chara and Asriel all decided to play a game of poker together in the Mafia headquarters, and the fox monster couldn't help but grumble at how because of Asriel, Chara ended up winning a lot of games. There was just no way he could get shit cards on so many occasions. Or was he really just that terrible at the game? "Surely you can win at least once." 

"Who said I'm letting her win?" Asriel rose a brow towards the fox. "I just never have good cards." The goat decided to say, because that was the only excuse he could give without telling the truth. Because the truth was, Blair was actually right - about letting her win. He enjoyed playing poker, but whenever he was left up against Chara, he never liked to let her lose to him, just because... Well... He was soft towards her. And it always made him smile how triumphant she acted when she had won a game; if he was able to be part of the reason for making her happy, even just for a moment, he loved it. 

"Yeah right. If I didn't know better I'd say someone has a little crush." Blair snorted, while Chara just stared down towards her cards, listening to the conversation as she wondered what Asriel's answer to that would even be. Surprisingly, he held his composure. But when you had been someone with a crush on a girl for so long, it was pretty easy to play pretend around her, act like he felt some way when he didn't. He could act like her best friend, when really, he loved her. Even if it hurt to pretend sometimes. 

"We're just really good friends, that's all." Asriel smiled, and the fact that he didn't break his facade made what he said extremely believable to Blair and Andrew, who glanced at each other and then the fox could only shrug, murmuring about how, okay, maybe he didn't have a crush then. Chara on the over hand, felt a slight sting at his comment, considering he was putting her in the friendzone. Still, like the goat, Chara's emotions were all going on on the inside, rather than outside. She just continued grinning down at her cards, before looking up, not seeming affected by Asriel's words. 

However, she was bothered. Not that she would say. Why would she say? She was Asriel's good friend, and she cared about his feelings. So, why would he affect his with her own? The last thing she ever wanted to do was stress him out.

Speaking of stress, Frisk had ended up having an extremely long day at her cafe job, and it had been pretty busy today, so that's why it had been a little stressful. She hated having to deal with the kind of customers that were just rude and unhelpful, because sometimes it was just difficult to remain patient for those kinds of people. Sometimes she questioned how she had so much patience for Sans back when he had been such a jerk towards her, when she had absolutely no patience now. Sans was lucky to have caught her at a time when she had the patience of a saint.

Not that she wouldn't still be patient for Sans, or her friends and family. It was just... Other people were harder to deal with, is what she was getting at. But, at least it really made all that stress start to slowly fizzle away, into nothingness, when she came home to her wonderful fiance, and her children. Actually, it was made even better, when she came home to the skeleton and the two kids in the living room, and to her amusement, Sans appeared to have his face caked in make-up, which must have been done by the two kids. It was hard not to giggle, as it definitely looked a little over the top, and Sans almost looked like a clown. But it was hard not to beam at the fact that Sans and their kids appeared to be spending quality time together.

"Mommy! Look! We made daddy look like a pwincess! Put on the tiara, daddy!" Luna told Sans, picking up the little, glittery, plastic tiara off of the floor beside her, before handing it to her dad, who ended up taking it and putting it on top of his skull. Frisk snorted. "Doesn't he look pwetty?" She questioned, while Leo didn't look so sure. But why would he when he wasn't exactly into all that girly stuff. He just wasn't really a girly kind of boy, at least he didn't feel like one. 

"He looks amazing. I see you've been having an eventful day." Frisk laughed, going to kneel down to kiss Sans on the skull, as he was sitting on the ground with the two little ones, and then she proceeded to kiss Luna and Leo on top of their heads too. "I'm sorry that I missed your little make-over. It's a shame I couldn't join in." Frisk continued to tease, while Sans smiled behind the lipstick that had just sort of been scribbled onto his face. He knew he probably looked like a sight, but if it made his kids happy, or kept them amused for a little bit, then he didn't really mind. 

"did ya have a good day at work?" Sans wondered, while Frisk let out a small sigh at such a question. It wasn't that it had been all bad, but she would be lying if she said she wasn't glad to be home. Sensing that she had a stressful day, Sans went to lean towards her to kiss her on the cheek, which earned a soft smile from Frisk. Of course, when he pulled away, it left a small mark of pink lipstick across her cheek, and Sans and even Leo couldn't help but crack up a little at that fact. "i may have made a little mark." 

"Well, if you wanted to give me a make-over too, you could have said so." When Frisk had said that, she only meant it as a joke. Little did she know that it would actually get her roped into their little make-up party, and not only was Luna drawing on her face with the make-up, but also Leo and Sans decided to join in this time, likely making her look like a bit of a clown like the skeleton. But to the kids, it was definitely a work of art, despite it only being scribbles. The day after that followed on with some more laughs, before the kids eventually grew tired and were tucked in bed. Because of such a day, both Sans and Frisk had to spend their time washing the make-up off of their faces before snuggling into bed, but it had been worth it to amuse their children. 

"I love getting to cuddle with you after a long day at work..." Frisk softly sighed, snuggling into the skeleton with a beaming grin, while Sans happily wrapped his arms around her, holding her close. It was weird, because you would think that after having such a hectic job as a member of the Mafia, it would be a piece of cake to work in a cafe. Somehow though, it wasn't easy, even if it had felt easy before. Maybe she was just missing her old job. 

"i'm glad. i love gettin' to cuddle with ya too." Sans chuckled. "it was a shame ya couldn't be with me to pick them up today - they're pretty excited about this play, even leo." Sans commented, remembering how they were yammering on about it among each other, without trying to give any spoilers. Even if they did accidentally spoil something without really noticing it, Sans tried his best not to listen, or to act like he had heard anything, as he knew the play seemed like a big deal to the little ones. 

"That makes me happy... I can't wait to see it. I'm sure they'll be amazing." Frisk said, as Sans nodded. Even if Leo didn't feel like he was much of an actor at the age of 6 years old, the parents still believed in him and still thought that as long as he did his best, then he could definitely be proud of himself, because they would be proud of him.

They would be proud of both of them.