"Sweetheart, we need to get going over to Dr. Gaster's house now, or I'm going to be late," Undyne's mother urged.

Undyne reluctantly pulled on her coat as her mother locked up the house. They started walking toward the direction of Snowdin.

"I hate going over there," the little fish monster whined. "Sans can't ever play because of his HP problem. And he's super weird anyway. And Dr. Gaster is always scolding me for touching his stuff."

"Then perhaps you shouldn't touch his stuff," admonished her mother gently.

Dr. Gaster opened the door when they arrived. His smile was genuine, but stern. "Hello, Pisca. Undyne's going to be here for the whole afternoon, is that correct?"

Undyne's mother nodded. "It is. Have a nice day, honey. I'll be back around six o'clock, alright?" she said, giving her daughter a kiss. Undyne promptly wiped it off and pouted. "I'm afraid she's in a bit of a bad mood. Hopefully she won't give you any trouble. And thanks again, G. This is a huge help."

"Think nothing of it. Come on in, Undyne."

After her mother had left, Undyne went into the kitchen, expecting to see Sans at the table eating something, like he usually was. "Where's Sans?" she asked when she found the room to be empty.

"Oh, he's been having special tutoring sessions with one of my colleagues. Turns out he's very interested in scientific matters," Gaster said proudly. "So I'm afraid he isn't here right now. But his little brother Papyrus is up in the room right in front of the stairs."

"Papyrus?"

"Oh, right—you won't have met him. He's been going to his own child enrichment program, but it was canceled for today. I'm sure he'd love you to play with him."

Undyne scampered upstairs, curious as to what this little brother of Sans' was like. The door to the room was cracked, so she pushed it open silently to see the back of a tiny little skeleton who was fiddling with something in front of him. Undyne turned back to Gaster, who was watching at the bottom of the stairs. "He's practically a baby!" she protested indignantly. "I can't play with a baby!"

Gaster smiled. "He's four years old. You're eight. That isn't that much of an age difference. He and Sans play with each other just fine, so I'm sure you can play just fine with him too," he told her. "He's far more active than Sans is, he doesn't have the same problems."

Undyne huffed. "Okay, fine." She trudged back up the stairs.

"Wait, wait." Gaster followed her up. "I really ought to be there when you introduce yourself, he can get very anxious around strangers. Papyrus, could you come here, please?"

The little skeleton dropped whatever he was playing with and ran over, slowing down when he saw Undyne. Then he ducked silently behind his father's legs.

"Come now, Papyrus, don't be shy. This is Undyne. She plays with your brother sometimes when you're at lessons, and today she's going to play with you."

Papyrus peeked out, then gestured for Gaster to lean down so he could whisper in his ear.

Gaster listened intently. "Of course she can, but you have to play with her first."

Papyrus bounced excitedly and came out from behind his father. He shyly took Undyne's hand.

"You two have fun now. I'll be in the basement working on my projects. Don't touch anything other than Papyrus's toys."

After he had gone, Undyne shook off Papyrus's hand. "Hey, stinko. If we're gonna play, then we do what I say, okay?"

Papyrus said nothing, only took her hand again and led her into his room. This totally confused Undyne; normally when she told people to do something, they just did it. But Papyrus didn't even act like he heard her.

The little skeleton climbed up on a bed shaped like a racecar and bounced on it, smiling broadly at Undyne. She glanced over the bed and gave him a weird sort of smile back. "That's, uh… yours, right?"

Once again, Papyrus didn't reply. He jumped off the bed instead and ran over to a bookshelf, pulling one of the books out. He held it up close to Undyne's face.

She took it from him and read the title. "'Peek-A-Boo with Fluffy Bunny'? What, do you want me to read to you? 'Cause I'm not doing that."

To her shock, Papyrus pulled her down onto the floor with a force far stronger than she would have expected from a tiny four-year-old and plopped himself down onto her lap.

"Um…" Undyne had no idea how to respond to that. "You got friendly real fast… guess I'll have to read to you, then."

Papyrus snuggled back into her chest and stared at the book, waiting.

The book was short and boring to Undyne—it was a very young child's book, after all—but she could help but feel a little warm and fuzzy when she got to the end and Papyrus started clapping happily.

"Okay… what should we do now?" Undyne asked.

Papyrus stood, took her hand again, and led her over to the toy he had been playing with earlier—a twenty-five-piece puzzle with large foam pieces. Some of the pieces were stuck together wrong.

"You want me to help you with this?"

Papyrus picked up a piece and attached it to another piece that didn't fit.

Undyne was becoming irritated with the skeleton's constant silence. "Hey, do you ever, like, say anything?"

Papyrus said nothing.

Undyne took the puzzles pieces from him. "Come on, say something. I saw you whisper to your dad earlier. Say something simple, like… my name! Say 'Undyne.' Come on, say it."

Papyrus lunged for his puzzles pieces, making a weird huffing noise when Undyne held them out of his reach. "Say 'Undyne' and I'll give them back to you."

Papyrus began to whimper. His mouth moved wordlessly, then he collapsed on the floor and covered his head with his hands, crying silently.

"Oh—oh, geez—" Undyne put the pieces down and patted his head in a panic. "I'm sorry! You don't have to say my name! Here, here's your pieces back!"

The skeleton sat back up, still sniffling, and began to fit the pieces in the wrong way again.

Undyne sighed. "Those pieces don't go together. That one goes over here," she instructed bossily, taking the piece from him again and putting it in its proper place.

Papyrus stood, his face screwed, and started stomping his feet and balling his fists in an entirely silent tantrum.

"Okay, okay! Fine! Put it where you want, I don't care!" cried Undyne, practically throwing the piece back at him.

Immediately Papyrus was back to his normal, happy self. Undyne sat back and watched as he put the puzzle together his own way. Eventually he gathered up a few in his hands and gave them to her, pointing to where he wanted each one to go. Undyne, confused but not wanting to risk another tantrum, complied.

When they were finished, Undyne stood back, expecting a mess of colors and shapes. What she found instead was that Papyrus had arranged the puzzle pieces according to color so that they made a rainbow. "Wow," she finally said in awe. "I didn't know you were smart enough to do that."

Papyrus beamed at her.

Then the distinct sounds of a stomach growling echoed throughout the room, and Papyrus clapped his hands over his belly.

"Oh, you must be hungry." Undyne smiled. "Well, we can't have that! Let's go get something to eat!"

Papyrus flapped his hands excitedly.

Going down the stairs with Papyrus took a while—he insisted on holding her hand and putting both feet on each step—but eventually they were in the kitchen.

"So what do you want?" asked Undyne.

Papyrus reached under a counter and pulled out a box of pasta.

Undyne stared at the label. "Spaghetti? You want spaghetti? But that's dinner food, and it's only three o'clock!" she said.

The skeleton only shook the box at her.

"Okay, fine. I think I know how to do it, I've watched my mom make it before." She started searching through cabinets for a pot. "Okay, I've got to fill this up with water," she told Papyrus, pulling one out from under the sink. "And then it's gotta get real hot. So you can't touch it or you'll get hurt."

Papyrus just watched in fascination.

Undyne had to pull up a stool so she could reach the faucet to fill the pot. As it turned out, a pot of water was much heavier than she expected. "Put that box down and help me!" she exclaimed as her arms shook, trying to keep the pot from dropping.

Papyrus set the box down carefully and toddled over, bracing his hands on the bottom of the pot as Undyne lowered it. But it was still very heavy, and they eventually had to set it down on the floor.

Undyne wiped her forehead. "Whew! I don't know how Mom does it. Guess we gotta rest for a minute before we put it up on the stove." She pushed the stool over in front of the oven. Then she looked at the box of spaghetti in curiosity. "Hey, do you think the noodles would cook faster if we just put them in now?" she wondered.

Papyrus picked up the box and held it out to her questioningly.

Undyne opened the box and shook the noodles. "Do you want to put them in?"

Papyrus took the box back and put the whole thing straight into the pot.

"No, silly!" Undyne laughed. "Take the noodles out first!"

Papyrus pulled the box out of the water and turned it upside down, promptly spilling dried spaghetti all over the floor.

Undyne sighed. "Well, you got at least half the box in there… I think. It's enough for us to eat, anyway." She placed her hands around the handle. "Okay, ready to help again?"

The skeleton child did his best to hold up his end of the pot, but it was entirely too heavy, and he dropped it as the two monsters tried to get up on the stool. Undyne dropped her end as well, sending the pot crashing to the floor, spilling water all over Papyrus and making the kitchen tiles a mess of water and broken noodles.

"Papyrus! Are you okay?" Undyne cried, partially because she was scared of getting in trouble, and partially because she was genuinely worried about Papyrus.

Papyrus let out a loud, high-pitched laugh, the first thing Undyne had actually heard out of his mouth all day. The skeleton picked up the now-empty pot and put it over his head, his giggles echoing in the space.

The front door opened. "What's going on in here?" Gaster demanded, striding right into the kitchen. "I heard a crash—oh."

"Hi, Dr. Gaster," said Undyne sheepishly. "We got hungry."

"Then why didn't you ask me to get you something?" he replied angrily. "You could have gotten hurt." He stared at his son sitting on the floor, soaking wet, still giggling underneath the pot. Gaster squatted down and lifted the pot just enough so he could see Papyrus's eye sockets. The child laughed delightedly again and covered his father's eyes with his hands and suddenly took them away, his own little game of peek-a-boo.

Gaster couldn't stay angry. It was rare that Papyrus made any sound in front of strangers, but he was comfortable enough to laugh in front of Undyne—he must really be having fun with her.

"Alright, you two. Go back up to Papyrus's room. I'll clean up down here and then come up to help Papyrus change clothes, and then we can come back down and have some carrots. And then I think it'd be best if you played outside."

Papyrus hopped up excitedly—he loved to play outside!

Once everyone was cleaned up and fed, Gaster led them outside and showed them where the basement door was. "I'll be in here if you need me—I'll keep the door open so I can hear you. But you are not to go into the woods, understand?"

Undyne nodded, and Papyrus bounced a few times on his feet.

"Good. Have fun."

And have fun, they did. Undyne got to see just how rambunctious Papyrus could be; he bounced around everywhere, zoomed around corners, and threw snowballs that really hurt sometimes. Undyne didn't have to be so careful around him like she had to be with Sans.

She was really having a good time.

Such a good time, in fact, that when her mother came, she was bitterly disappointed and begged to stay longer. But Pisca insisted on going home to get dinner ready.

"Thank you again, G. This was such a huge help," Pisca said to Gaster. "And I hope Undyne was good to you," she added to Papyrus, who was currently being held in his father's arms.

Papyrus unhooked his legs from around Gaster's waist and wiggled around until Gaster put him down. The little skeleton faced Undyne, glancing at her mother uncertainly before huffing and opening his mouth. "Thank you for being my friend," he said, pronouncing each word slowly and precisely.

Undyne stared up at Gaster, who smiled.

"He doesn't usually talk to people unless he's comfortable around them. So count yourself lucky, Undyne. He likes you. Although that probably means he'll talk your ear off now," he said, rubbing his son's skull affectionately.

Undyne laughed. "That's okay with me, as long as he can talk about cool stuff."

Papyrus suddenly threw himself into Undyne's arms. Undyne, though taken aback at first, hugged him back.

Papyrus was such a weird kid, but also a really cool little dude in his own way.

And she couldn't wait to play with him again.

As Undyne and her mother walked away, she asked, "Hey, Mom?"

"Yes, dear?"

"When can I go over again?"

oooooooooo

A/N: hey y'all! here's another Tumblr request.

the title is a reference to a Steven Universe episode, if you're curious.

both of my beta readers screamed that this was too cute. I hope u all think so too.

enjoy!