While the kingdom of monsters didn't offer that much in the way of space, there was still enough variety in the land to give the creatures who lived there some choice in where they wanted to live. If someone wanted to live alone, they lived in The Ruins. If they wanted to live somewhere cold or scenic, they lived in Snowdin. If they ever wanted to cook their hotdogs by sticking them out the window, they lived in Hotland. If they wanted to meet new people, they lived in New Home. If they liked anime, they lived by the dump. And, of course, people lived in Waterfall because…

They wanted to get wet.

That was one of Temmie's favorite things about living in this part of The Underground. She could go for a swim, get some water for her special tea(m), refill a squirt gun, or have an impromptu wet Tem-shirt contest whenever she wanted. But today, as she hopped towards one of Waterfall's more secluded rivers in her cardboard box, she wasn't there for any of those things, however. No, she was there for some grim, serious, downright dirty business…

"Shouer Tem!" The dog/cat/girl cheered as she jumped out of her box, revealing that she was wearing a tight yellow bikini with blue spots that just barely held back her massive breasts, or her incredible bouncing booty. Although it was undeniable that she looked absolutely stunning in attire that tight, that was actually never the intention; she simply got the swimsuit when she was 15 and never bothered to to buy a new one.

"Ok, boxy, u wat here," Temmie said as she gently set the box aside far away from the edge of the river that stood behind her. "Tem wants to take u with, but Tem dont wan u tu end up liek ur sisters."

With her cardboard friend now safe, Temmie ran towards the river so fast that her smiling face could barely keep up with her. Once on the riverbank, she jumped straight into the air, did a little spin, and landed into the water with a loud splash.

"Aaaaah… Tem feel so relaxed…" Temmie's face sighed as it floated on the surface of the water while her body twirled around in the slow current underneath. "Dis iz y dis is Tem's favorit shouer spot!"

After a few moments of relaxing underwater, Temmie's body swam back to the surface and collected its face before she doggy/kitty/human padded her way over to a nearby waterfall. There, she stood up in the shallower waters and let the titular waterfall run down over her titular tits. The glowing, glimmering water made the monster girl look almost like a goddess as she ran her hands across her body. The light showed off her curves perfectly, and it was hard not to drool at every single one of them.

And it wasn't just the omniscient narrator who thought this either; it was also a certain, jealous woman who was secretly watching from a nearby tree.

"Wow… look at her go!" Moldbygg thought to herself as she peaked out from behind the tree's black leaves. Her large, green, gooey form was putting a strain on the branch she was spying from, but she was so focused on the delectable monster girl in front of her that she didn't even notice. "She's so beautiful! I… I don't think I've ever felt this way about anyone before. I… I want to get closer to her! I want to hang out with her! But… what if she turns me down?!"

Moldbyg worried over this theoretical rejection for a few moments before they were interrupted by a loud wooden crack. The next thing she knew, the jelly girl was face-flat on the ground, dazed and out in the open.

"Huh?" Temmie gasped as she turned back towards shore. "Who's ther?"

"Oh, uh, hey, Temmie!" Moldbygg said as casually as she could. "Funny running into you here! I was just here to, uh… shower! Because this is my favorite spot!"

"Really? It iz!?" Temmit gasped in shock, causing her chest to bounce and Moldbygg's body to quiver. "Itz mine two!"

"Wow, what a coincidence!" Moldbygg replied, keeping her composure for the most part even as she found it hard not to just stare at Temmie's wobbling chest. "Say, since we're both here and all, do you think we could… hang out a little?"

"Sur! Dat sounds liek fun!" Temmie smiled and walked her way over to the riverbank, the water shining as it flowed between her smooth thighs and her breasts bouncing so much that it was a miracle that her bikini didn't break, or that she didn't hit herself right in the face. "What do y want tu do?"

"Well, to be honest… just watching you swim and talking with you would be fine with me," Moldbygg admitted, smiling from just being so close to the object of her affection.

"Ok, dat sounds liek a gud plan!" Temmie was about to dive back into the water and start swimming around, but a sudden cramp in her right shoulder stopped her at the last moment. "Aaah! Nut gud!"

"Oh! Is something wrong?" Moldbygg asked, concerned.

"Tem fine, iz just… my strap keep hurtin ma shulder…" Temmie complained as she rubbed the sore spot in question. "Tem wonders if tem needs nu soot."

"No!" Moldbygg gaped. "Uh, I mean, I'm sure that won't be necessary! I'm sure you're just tense from a long day is all."

"Well, Tem did chew her tem flakes extra hard dis morning…" the pale girl replied as she tapped her chin in thought, her breasts bouncing all the while from that movement alone.

"Yeah, you work really hard, Temmie! All you need to do is relax a little, and you'll feel as good as new!" Moldbygg insisted. "Oh, I know! I could massage your shoulders a little if you want! I'm sure that will help!"

"Relly!? U'd du dat for Tem!? Tank u so much!" Temmie pulled Moldbygg into a deep hug, her curvy body imprinting itself onto the jello girl's form in a way that Moldbygg swore that she would never forget. "Les get started nao!"

Temmie turned herself around in the water and sat down onto the edge of the riverbank. Her massive rear made quite the dent in the smooth sand underneath her body, and her tail wagged eagerly as she waited for the girl behind her to start her massage.

Moldbygg had to reform herself after being hugged by Temmie so hard, but beyond that she wasted no time in getting in position behind her busty friend's body. Temmie let out a soft coo as she felt her new friend's cool body come into contact with her shoulders, and Moldbygg had to stop herself from breathing too heavily as she felt her crush's warm, soft skin start to emanate through her body.

"Okay, just… let me know if I do anything that feels bad." Though she wasn't really used to squeezing or pressing anything, Moldbygg still tried her best to start massaging Temmie's shoulders. Her gooey fingers pressed down hard into Temmie's skin, squishing at first, but soon growing firm enough to press down into the muscle. Temmie let out a grateful sigh as she felt her muscles start to loosen, her rack giving a massive bounce as they fell with her shoulders.

"Aaaaaah… Moldy iz real gud at dis!" Temmie said as the cat/dog ears on the top of her head twitched in appreciation. "Kepe going! Tem hav a lot ov 10shon tu work out!"

"Trust me, I wouldn't stop this for anything, Temmie~" Moldbygg replied as she began to work up a rhythm, pressing deeper Temmie's shoulders each time and switching spots whenever she felt the ones she was working were loose enough. "Jeeze, you really were tense. Maybe you should get massages more often."

"Relly? Tem no wan tu b a burden," Temmie said as she considered the idea.

"Don't worry, it won't be any trouble at all~" Moldbygg replied, her slimy texture relaxing Temmie more and more. "You know, Temmie, you really do have quite the beach body. Your curves must make all the other, uh… Temmies jealous."

"Nut relly." Temmie gasped and kicked her legs involuntarily in the water as Moldbygg worked out a particularly hard kink in her back. "Tem never gt any complemints. Evn wen Tem wurk hr best box, noone evah say anythin."

"Well, that's just a shame then! If they can't see what a beauty you are, then that's on them!" Even though Moldbygg knew that jello wasn't the best for holding onto things, she couldn't help but seize the opportunity that lay so clearly in front of her. Two opportunities, actually, both of whom were big and round and made the most amazing noises whenever they bounced.

"Wha!?" Temmie shouted in surprise as she felt her massive tits squished again and again. "You r tuching Tem's tatas!"

"So? It feels good, doesn't it?" Moldbygg asked, her apple flavor especially thick on her breath as she through her face up next to Temmie's."You want me to keep going, don't you? Do I have your permission?"

"Tem… Tem nut feeling… bad…" Temmie replied between wimpers, her voice somehow growing both more and less hard to understand over time. "Tem… nut mind… iv u keep going!"

"Mmm, that's what I wanted to hear~" To show her appreciation, Moldbygg latched onto Temmie's nipples and twisted them, causing a strange sensation of warmth and cool rushing through her chest at the same time. "Trust me, Temmie, you're not going to regret this! I may not have a degree like you do, but that doesn't mean I still I can't teach you a few things."

"Tem can alredy tel… Tem mayk good choice!" As she spoke, Temmie leaned backwards into Moldbygg's body, allowing slime girl to act as her cushion. "Aaah… ur body iz even mur amazing dan Tem's. Iz so soft an squish. Tem could lay her four evah!"

"You're too kind, Temmie! My body isn't really all that impressive - especially compared to all the other jello girls out there." Moldbygg kneaded Temmie's pillowy chest flesh like it was dough, stretching it in every direction to see what kind of pleasurable reactions she could squeeze out of the adorable solid girl. "Mine can take on any shape it wants, but you… you're always sexy. It's like you were carved by the world's best sculptor, and left for the world to see - but only I get to truly appreciate you. It is both a shame… and an honor~"

Temmie didn't respond this time, unable to do anything but whimper as the dog half of her tongue hung out of her mouth to help cool her down. If it wasn't for the fact that she had just gone for a swim, Temmie's bikini panties would have undoubtedly been soaked already from the sensations from her breasts alone. And those feelings just kept getting more and more intense, refusing to die down as they built up and made Temmie's mind swirl.

"Your nipples are so puffy, Temmie… they really must have been waiting for a good massage like this~" Moldbygg cooed softly into Temmie's lower set of ears. "Inverted nipples, puffy areola… I can tell just by looking at them that they're screaming 'squeeze us, squeeze us'!"

"Tem.. hav natty bubes… Tem hope… u forgive Tem," Temmie whimpered back quietly.

"Oh, don't worry, I promise they'll be good boobs by the time I'm done with them." Moldbygg reached under Temmie's breasts, lifted them up as high as she could, and then let gravity drop them back down. The force of her tit's own gravity pulling down on them seemed enough to force Temmie through a small orgasm, though she tried to hide it as best as she could.

"Now then, let's see what else we can do with this little body of yours, shall we?" Moldbygg finally moved her hands away from Temmie's breasts and began to rub them up and down the pale girl's body. Temmie could feel butterflies in her stomach as Moldbygg's hands ran across her navel, her waist, and her thighs. In the end, though, Moldbygg simply couldn't keep her hands away from Temmie's breasts for that long and soon returned her focus to them.

Deciding not to leave any part of Temmie untouched, Moldbygg slimmed down the fingers on her right hand and brought them to Temmie's right nipple. Careful not to hurt her new friend, the slime girl brought two of her small fingers to the nipple's 'slit' and slipped them inside, allowing her to stimulate Temmie's teat directly with her slick jello form.

The sudden new sensation was so strong that Temmie had to cross her legs to stop herself from spraying more water than the nearby waterfall, but even then she couldn't stop herself from having two orgasms from the strange feeling around her teat alone. Moldbygg smiled at Temmie's reaction and brought her other free hand to the girl's other nipple. Working her fingers inside both slits now, Moldbygg played with Temmie's massive tits from inside to out, squeezing them tightly and slowly fishing out her hidden teats until, finally, they were exposed to the cold moist Waterfall air.

If Temmie's nipples weren't sensitive already, finally being fully exposed definitely sent their tenderness through the roof. Temmie was now moaning with every single squeeze and twist of her breasts, and her nipples were so hard that they could break through the barrier. Soon, the sensations became so much that Temmie couldn't even sit up straight anymore, and Moldbygg had to catch her when she began to fall over.

"Ah… surry… Tem.. tuckered… tout…" the bikini-clad girl gasped as she rested in Moldbygg's arms.

"Don't worry, you can just lay back and relax~" Moldbygg smiled and laid Temmi's body down onto the black grass, allowing her body to glisten and glow with the reflections of the shimmering stones on the roof of the cave. "I'll take care of everything!"

Adjusting her position, Moldbygg grabbed ahold of Temmie's right breast and clasped her mouth around her pert nipple, swirling her tongue around it it and causing Temmie's whole body to quiver nonstop. Her other hand, meanwhile, slowly moved its way across Temmie's soft belly and dipped its way into the panties of Temmie's bikini bottoms. Moldbygg could feel Temmie's pussy twitch the instant she touched it, but the jello woman didn't slow down. Instead, she just ran her slick fingers right over Temmie's hard, sensitive clit and shoved her fingers right inside her tight hole.

Fresh off their experience of stretching Temmie's back muscles, Moldbygg's fingers swirled around and stretched Temmie's insides as much as they could. They spread her walls wide, massaged her most sensitive spots, and began to pump in and out.

"Moldy… maek Tem… feal zo gud!" Temmie's pants grew more ragged the faster Moldbygg thrust in and out of her, her body barely handling the pleasure she was now feeling from both above and below. "Tem feel… liek Tem… iz gonna explod!"

"That's okay! I promise, I'll be here to pick up all the pieces and put you back together!" Moldbygg said in between teases of Temmie's nipple. "So go ahead and explode! Squirt enough juices to make the river overflow! Show me what that beautiful body looks like when it completely loses control of itself!"

"Tem cum… tem coom… tem… tem… tem cuuuuuum!" Temmie screamed at the tops of her lungs as the pleasurable sensations reached a crescendo. Moldbygg could feel Temmie's pussy squeeze so hard around her that it threatened to squeeze her pliable fingers right off, and the writhing of her body sent tons of pleasurable vibrations through Moldbygg's form. Moldbygg didn't finish herself, but to her that didn't matter. She was perfectly content with watching Temmie's face cry out in pleasure, her stomach twist and turn, and her breasts shake even more than the bounciest jello girl Moldbygg knew.

Unable to control herself any longer, Moldbygg pulled Temmie into a fierce and fruity kiss. Temmie, in her dazed state, had to resist chowing down on the other woman's tasty tongue, though it seemed as though Moldbygg was so enraptured by lust that she might not have even minded. In the end, Temmie just moaned and screamed into her new friend's mouth as her orgasm slowly ended and they were left alone with nothing but the sound of their kisses and the babbling brook beside them.

"Tem… ver… imprussed…" Temmie spoke when the kiss finally broke, doing her best to catch her breath. "Tem wants tu no… cun we… du dat again sumtime?"

Moldbygg smiled back at the girl and hugged her close to her body. "I think I'd love that, Temmie."

With that, the two bundled up against one another, with Temmie panting like a dog, mewling like a cat, and snuggling like a woman with her girlfriend as they both let the sound of the river put them to sleep.