Love is a battlefield

Setting:

Undertale [Wartime]

Characters:

Gaster

Grillby

Summery:

Love within a battlefield between a medic and a warrior. In an effort to protect the front Grillby transforms into a monstrous flame, but with consequences. Gaster is put in charge of taking care of the warrior flame, though they get closer than they thought they would. Gaster/Grillby Rated M content

Hello! This is another Undertale Fic by TempestJewel and a fanfictioner Hope you enjoy! Remember to comment or message us if you have any questions!

So WARNINGS for this chapter: sexual rated M content. it's not marked.

-A monstrous flame-

Grillby was exhausted. He had used all of his energy earlier to becoming a massive monster of flames and scorching hot lava. Now his flames were low and withering as the campaign moved on to find their camp site. The rumbling of thunder in the distance gave him nothing but fear and he clutched his armor.

Gaster was pissed as he rushed through the camp. his best friend had nearly killed himself with that stunt and he knew he was probably dust on his feet, but he had to find him since it was about to rain and he wanted to dust him himself for pulling such a stupid stunt.

Grillby stumbled as his boots caught on a rock. His knees buckled and he landed on the ground face first. Grillby groaned laying there for a moment.

"There you are!" Gaster said turning his soul blue and lifting him "stars you look awful!" He said eyelights wide "have you eaten?!"

Grillby gave a small tired chuckle at the view of his friend. "Hello Dings..."

"Don't hello me you jackass! I heard you almost died!" He said shaking him in the air a little

Grillby chuckled his head lolling at the shakes "sorry… there was too many of them and you probably saw how many of us were low on HP… i did what i had too."

Gaster frowned looking down "i-I know..." He said carried Grillby after himself "but you... I..." He growled "I hate your stupid life saving butt!" He said taking him to his med tent

Grillby gave a soft laugh "i know Dings. I know. I'll try to be better next time… thanks Dings for taking care of my sorry flames."

Gaster laid him down and poured him a cup of gasoline and mixed it with some dry cedar and some lemon grass "drink this" he said. the gasoline and cedar were to help him burn better the lemon grass made it mildly taste better.

Grillby took the cup downing it in one go. He grimaced at the strange flavor, but his flames instantly sparked and grew brighter. Swinging his legs over the side of the bed and sat up "thanks Dings. Well I better get back to the watch."

"Someone took your place you are staying in that bed" he said crossing his arms frowning sternly... As sternly as the nerd could anyway.

Grillby frowned standing up "Dings really i'm fine. They need me, plus i'm sure there are plenty of guys that need you more than me."

"Nope it's not my shift the king ordered me to take care of his best warrior" he said "and that's you"

Grillby's flames flushed a light pink as he gave a small crackling whine. "I don't need coddling and I'm sure that the king never ordered that or you would be over in Gerson's tent."

"Gerson isn't the dumbass that turned into a huge beast to save the front."

Grillby's flames sparked leaping up "i-i you know why i did it! The front isn't as skilled-i had too-you know what i don't have to defend myself to you." Grillby pushed past the skeleton striding out of the tent.

Gaster growled and grabbed his arm "don't walk away from me! Do you know how terrified I was?! I didn't even know if you had survived until a messenger told me! A messenger! I am not allowed on the front! You know I'm not! What if someone had really hurt you?!" He said tearing up. Gaster wasn't allowed anywhere near front lines as the last skeleton the king had ordered him from being a battle mage to a medic. An effort to preserve the skeleton bloodline. The skeletons had been targeted by both monsters and humans at the beginning of the war since both sides had people who saw them as a sick combination of human and monster. Grillby and the royal family was all Gaster had left.

Grillby sighed his breath hot and heavy on the skeleton and he yanked Gaster into his arms. Holding him close and resting his head on the other's skull Grillby mumbled, "I'm sorry… i wish you could be out there. I... i was scared too. I was terrified that i wasn't going to be able to turn back. If i had you out there… i'm sorry. I wasn't thinking." Grillby's flames were low and he walked them back to the bed plopping down heavily, but keeping Gaster tugged tight to his side.

Gaster held onto him "stupid hero complex..." He said trying to hide his tears. "I'm glad you are okay" he said

Grillby gave a small snort "like i would leave you. Heh you would probably yell at my dust until i came back. I wouldn't have any peace with out you Dings."

"You're absolutely right" he said chuckling a little.

Grillby grinned pulling the other into a headlock and giving him a noogie. "Yeah i don't know what i would do without a boney nagging thing like you Dings"

"aaaah! Don't noogie the skeleton!" He said pushing at him

Grillby cackled loudly giving Gaster a kiss to his skull before releasing him.

Gaster blushed a bright purple "ew! You're gonna give me cooties!" He said covering his face the poor skeleton was so immature sometimes

Grillby flushed a light pink before chuckling "oh yeah?" with a smirk Grillby pulled Gaster close kissing both hands covering the skeleton's skull.

"Grillby! Stop that!" Gaster said but couldn't hide his giggles "I'm mad at you!"

Grillby gave a hot breathy chuckle giving Gaster's hand a final kiss. "Oh, are you? Well darn it. Guess i should just rest then. Doctors orders and all." Flopping back on the the bed Grillby smiled warmly up at the other. Grillby loved moments like these, calm after the storm.

Gaster laid next to him trying to stop his giggles "you're a tease" he said before sighing and taking his hand they had been best friends as long as he could remember. "You need to turn all those kisses to some girl or something... But then again I feel sorry for whoever they are gonna be with how many heart attacks you give me. And I don't even have one!"

Grillby chuckled squeezing his hand. "I could… but where would the fun be in that? Girls just call me smoken or hot headed. They just want me for my flames. At least with you i don't have to worry about getting doused due to doing something stupid… plus… i don't want any monster... I want you."

Gaster began laughing before snorting "sure sure a skeleton mother hen" he said rolling over to face him. "I find that Humerus!"

Grillby frowned his flames lowering mumbling "yeah punny… heh..."

Gaster looked at him frowning "wait... Grillby... Were you serious?" He asked

Grillby's flames went bright pink "n-nah just joking around right? I mean we're best friends w-why would we want-need to be more. Plus i mean it's not like monsters aren't fighting to jump your bones i-i mean like you said i need to find some girl or something..." Grillby was running his hand through his flames nervously after his word vomit. he should have just kept his mouth shut! why now of all times.

Gaster frowned softly and took his hands "Grillby... No one wants me. I'm a skeleton, the last skeleton. I just... Didn't think anyone would want me. I'm picky and very over bearing... B-but if you er..." He said blushing bright purple

Grillby looked between their hands and Gaster's blush. "If i..."

"If you um want to try to be more... Iwouldlikethat!" He said the last coming out in a rush

Grillby's flames went bright pink the ends curling almost into heart shapes. Grabbing Gaster's shoulders he yanked him into a fiery kiss. Grillby closed his eyes feeling cool teeth against his flames. He let out a small sigh against Gaster's teeth. Grillby has waited so long to do this to the skeleton.

Gaster made an alarmed noise as he was jerked forward. he had never seen Grillby so beautiful and quickly melted into the kiss. "Grillby..."

Grillby was slowly able to open his eyes and started to ease out of the kiss. Caressing Gaster's cheek Grillby smiled "sorry if i'm moving too fast… i've just been waiting so long to do that. Heh you're a good kisser or kisse."

Gaster blushed "you aren't going to fast. I may have... Been dreaming of this myself" he said

Grillby chuckled leaning forward licking a hot stripe up Gaster's collarbone to his cheek "good to know."

Gaster gasped and shivered clinging to his arms "Grillby..." He panted and pressed close

Grillby hummed giving Gaster a peck to his skull "yeeesss?"

"Stop teasing" he said whining

Grillby froze. "Gaster… do you want to go all the way? Are you sure? If you're not comfortable we can just cuddle and makeout."

Gaster blushed "I um... What do you want!" He said blushing brightly

Grillby gave him a blank look stating simply "i want to fuck you into this mattress until you can't walk. However, i'm not going to force you to do anything. Gaster, i love just kissing you. I could hold you in my arms and be a happy little flame forever… so what are you comfortable in doing?"

Gaster was wide eyed at his declaration before covering his face. "Um... Well we both have shifts tomorrow... So maybe don't leave me unable to walk?" He suggested the closest he could bring himself to saying 'fuck yes take me'

Grillby laughed pulling Gaster close "whatever you want Dings. You're so adorable."

"No I'm not" he said and kissed his cheek. "I'm sexy" he said with a straight face before giggling

Grillby was brighter than he's ever been since the war started. Running a hand down Gaster's shoulder tracing his bones until he reached the skeletons hips. "You are very sexy."

Gaster shivered under the touches they felt nice. he began touching back, his delicate hands going over and undoing the straps on Grillby's armor, much more complex than the robe Gaster had on.

Grillby smirked helping Gaster get his armor undone and off before turning to the other. Slipping a hand under the robes entrance near the skeletons skull. Grillby caressed the bones slowly sliding the robe off Gaster's shoulder before moving on to the other shoulder. Grillby hummed giving Gaster small kisses to his top ribs. "You are beautiful Dings."

Gaster smiled when Grillby helped him but hugged himself when his girlish frame was revealed "you aren't gonna call me a girl again are you?" He asked it was a spat they used to have when they were teenagers Grillby poking fun at how he inherited his mother's figure.

Grillby gave a hot sigh to the other's ribs. Grillby leaned up kissing Gaster's teeth. "You are beautiful Gaster. I don't care what you look like, but if you must know… you are the most gorgeous looking skeleton i have ever seen. You have the sexyest bones whatever figure you inherited them from. You are my Dings, girl, guy, my skeleton. I only commented that when we were younger was because you are better looking than all the girls i've seen, guys too… feel better?"

Gaster blushed "yes..." He said and kissed back and allowed the rest of his robe to drop "I um can summon my ecto body... But what parts do we want?" He said running his hands down his own bones before running his hands over Grillby's with a purr "you are so warm and strong..."

Grillby gulped loudly his flames going bright "i-i didn't know you could-i mean i assumed-you can make-oh stars..."

Grillby nodded and then had an idea and smirked "oh yes I can... What would you like?" He purred and did a heel turn summoning his lavender body when he turned back he had c-cup breasts and a slit he tried not to look embarrassed. "This? Or maybe..." He turned again and when he came back he looked like a male through and through, before doing it again and looked like a male with a slit instead of a cock. He was blushing wildly "what would you like?" He asked

Grillby's jaw hung open wide and his flames seemed to be flickering dangerously as if caught in a strong wind.

Gaster watched him allowing his body to vanish "um Grillby? I-if it's too much I can just make a hole" he said nervously had he ruined this by being weird?

Grillby instantly shut his jaw turning away from the other, but his flames gave him away as the flushed a bright pink "n-no i-i-i..." Grillby took a deep breath. Why was he becoming so flustered at seeing Gaster this way. Maybe it was because he had assumed the other would be more embarrassed and just want to hold hands. "I like it. I-i'm just… surprised… maybe a little embarrassed. B-but you look great in all of those. Perfect. I-i guess whatever makes you feel comfortable?" Grillby gave a small sigh muttering as he ran a hand through his flames "stars i'm a mess"

Gaster frowned "I ruined it didn't I..." He said turning away "I'm sorry... This is what I get for trying to be bold stupid stupid..." He said to himself. He wanted to try and make this easier and he just made them both uncomfortable

Grillby shook his head "no no you are perfect. It's my fault… i lied..." Grillby nervously clutched the sheets.

"Lied?" Gaster asked hugging himself "about what?"

Grillby took a deep breath though his voice shook. He would be such a disappointment to Gaster. "I-i don't know anything. All i know is some stuff i found in a book. I. i've never done this before… i'm still a virgin..."

Gaster looked at him before sighing in relief "oh thank the stars!" He said and collapsed next to him "I am too! I was um just trying to impress you..." He said sheepishly

Grillby looked to him in shock. "Really?! Well you did a dam good job at it Ding."

Gaster blushed brightly "I um... Have a lot of time on my hands... And maybe think about this a lot... Or a little" he said looking toward him "since we decided we are both liars... Um did we still want to try?'

Grillby blushed but nodded "only if you do."

"I would um like to try maybe" Gaster said "I mean we already naked" he said

Grillby chuckled pulling Gaster into his arms. "Well okay all knowledgeable Skelebabe. Teach me your sexy ways."

Gaster blushed "um let's start with... Kissing?"

Grillby chuckled leaning forward and kissing the other's teeth. He prodded teeth with his fiery tongue asking for entrance. his hands wandering the perfect bones in front of him.

Gaster eagerly opens his mouth his own tongue meeting him he tasted a bit like grapes... Not medicine ones, but sweet ones that used to grow near their homes

Grillby groaned at the flavor eagerly exploring the other's mouth.

Gaster clung to him moving his tongue with him. Grillby was so hot, but it didn't burn his bones.

Grillby gave a small moan as Gaster's cool tongue wrapped around his hot one. Moving his hands down Gaster's spine Grillby cupped Gaster's pelvic bones pulling the other closer. Fondling the bones Grillby heated their kiss, drool seeping down eachs chin and his flame sparking wildly.

Gaster moaned and rocked into the touches his own magic sparking wanting to form but unsure what form to take.

Grillby groaned as Gaster rocked into him a large flaming cock dropping down away from his form and making itself known.

Gaster looked at it and his eyelights widened and turned into hearts "oh Grillby! Its huge!" He said his body sparking to life with a slit wet and eager to be filled.

Grillby blushed at the praise. Grillby ran his hands slowly down Gaster's bones until he reached the slit. Slowly he rubbed the small budding nub of the clitoris. "Dings… you look so eager."

Gaster gasped arching into the touch he never really played with himself not since he was a horny teen dreaming of his best friend so this was all sensitive. "Ah~ I've been dreaming of this... J-just a little excited!" He said and buried his face into his neck and licked it.

Grillby shivered at the lick giving a small groan of approval. Continuing his ministrations on the nub Grillby's other hand crept to the lovely wet folds. Rubbing his heated fingers over the folds dipping slightly through the lips. "I'm excited too. I've waited so long to touch you."

Gaster gasped as more hot fingers went over his slit and between the lip, he whined rocking them. "I'm so glad..." He said this all was a dream come true

Grillby chuckled wiggling his fingers deeper inside of the other, starting to stretch him.

Gaster panted and spread his legs for him trying to make it easier. He was blushing brightly.

Once he had three fingers securely inside the other, Grillby started to pump them in and out. "Dings… tell me if i hurt you or if you want to stop."

"I will..." He promised. it burned a little but he knew it would go away and soon it did. "Heh..m you're just burning me up..." He said

Grillby let out a snort leaning on Gaster's shoulder as he chuckled. "You are ridiculous Dings."

"You mean... RiDICKulous" he said his slit squeezing on his fingers.

"Psh heh heh i think that's more me, you don't have one… yet." Grillby smirked pulling out his fingers with a squish.

Gaster spread his legs "want to correct that?" He purred feeling more relaxed now that they made a few jokes.

Grillby blushed nodding

Gaster cupped his face and kissed him "I love you Grillby..." He said

Grillby froze gaping his flames sparking pink and curling into hearts. "I-i love you too Dings."

Gaster blushed smiling "I'm glad..." He said and nuzzled him "take me please" he said softly

Grillby grinned kissing and nipping Gaster's neck "how could i say no to you my dear." Grillby took Gaster's hips and lined him up before slowly easing inside him with a groan.

Gaster moaned at the kisses and nips before hissing softly as he was stretch and held onto his mate. it was so hot!

Grillby rocked slowly as he eased in trying to make it feel good for his lover. Licking and sucking on one of Gaster's ribs Grillby created a hickey releasing it with a pop he moved to another rib. "I'm going to make you mine Dings."

Gaster's soul quivered "yes... Please... Make me yours Grillby" he said moving up closer hands raking through his flames as he moaned

Grillby gave a low moan as he finally was fully inside Gaster. He licked at Gaster's neck before starting on making another dark hickey. Grillby started rocking inside Gaster giving slow shallow thrust, moaning lowly into bone as he did.

Gaster moaned as he was filled and he tilted his head for Grillby to have more room .

Grillby gave a crackling chuckle slowly moving to deeper and quicker thrust. "You sound-look absolutely ravishing… alluring… magnificent…" Grillby peppered the other's bones in loving kisses

"You do too" Gaster said and bucked under him meeting his thrusts while his slit pulsed around he cock

Grillby groaned pulling almost completely out before plunging deep inside his skeleton lover quickening his pace. "Ah~ you make it hard to keep myself in control."

"I can take it" Gaster promised crying out in pleasure as he was pounded harder. they certainly weren't being subtle though most who passed by thought it was about damn time

Grillby's flames flared grabbing Gaster's legs he tossed them other his shoulders pushing Gaster roughly into the bed. Grillby husked out his flames flickering with a lustful glow "I'll hold you to that Dings. Heh you didn't want to walk tomorrow did you?" Licking and biting at Gaster's clavicle Grillby started a rough quick pace.

"They can ah~ live without me~" he moaned and writhed it was so hot it was burning! He loved it! Needed it! Grillby was the only one for him and he made sure he knew it. his purple soul popping out calling for his partner's.

Grillby gave a groan loving how debauched his lover sounded. Seeing Gaster's soul he gave a startled gasping. "Oh Dings..." his flames turning a bright orange at the sight, he loved Gaster so much. Grillby grunted balancing himself with one hand as he continued his pounding into his skeleton. The other Grillby used to cup the soul bringing it to his lips giving it a soft kiss. "I love you so much Dings..." with a smirk Grillby gave the soul a lazy lick. Moaning as he gave a harsh thrust and licked another stipe up the soul. "Sorry i just can't help it when you look so delicious Dings"

Gaster moaned as their souls mixed their bond solidifying. He clutched Grillby moaning as he was filled; feeling the heat of his lover's fire but not burned by it like their surroundings

Grillby panted grinning. Giving Gaster loving kisses up his ribs until he reached his lovers teeth. He murmured to the other as he gave his kisses "Dings... So beautiful... Love you... The way you look... So debauched... So lovely... Mine... My Dings."

Gaster smiled and kissed back "and you are mine... So fierce and strong..." He said and looked down at himself "no one will be doubtful of your claim... or mine" he said and pointed to his flaming head that now had lavender tips

Grillby blinked glancing up and catching sight of the tips. Grillby gave a small squeak of embarrassment hiding his face into gasters shoulder and giving a whine "Dings..." the smell of smoke started to form.

Gaster chuckled before sniffing "what is that-holy crap!" He said jumping up the bed was on fire "Grillby get up so I can put it out!" He said

Grillby scrambled off the bed falling to the floor "oh stars! Gaster i'm sorry!"

Gaster put it out blushing "don't be sorry! I just can't believe we set it on fire..." He said

Grillby's flames lowered as he sat on the floor "it's my fault. I should have been more careful… sorry. I-i should probably go to the lookout anyway."

Gaster frowned "Grillby you have till tomorrow off and it's my fault too" he said blushing "I don't really regret it either" he said

Grillby blushed looking down "i… i don't regret it either. I love you a lot Dings… but i burned your bed. Dings you know i'm not the safest person to be with. What if-what if i burn you..."

"I don't think you can Grillby" Gaster said "I didn't feel the burn I just smelled it... Here make a fireball we'll test it" he said

Grillby's eyes widened, his flames turning a sickly brown as he scrambled back "what! N-no! This is what i'm scared-terrified of. I would never hurt you. Y-you can't asked me… please don't ask me too."

"Grillby! Don't be afraid! I'm telling you it won't burn me" he said "I won't even touch it I promise" he said and kissed him gently

Grillby gave a small sniffle curling his knees to his chest, but didn't say anything further. It physically pained him to think about harming the other.

"Now you are being silly" Gaster said and sat next to him nuzzling his neck and licking it soothingly. "Would I ever put you in a real position to hurt me? We've soul bonded and I didn't feel any burns when the blanket was on fire" he said

Grillby whined leaning into Gaster, though he gave the other a pouty expression.

Gaster chuckled and kissed him nibbling his pouty lip

Grillby crossed his arms, but leaned into the kiss. He didn't speak though deciding to continue his silent treatment.

Gaster slid onto his lap straddling him. "Oh is that how it is?" He cooed and rubbed their crotches together "maybe I know what can loosen your lips..." He said blushing, his cock forming against Grillby.

Grillby gave a small whiny groan at Gaster's movement. Blushing hard Grillby turned to look away from Gaster, though his hips twitched excitedly against Gaster's cock.

Gaster purred and began grinding against him "hmmm you like?" He cooed

Grillby groaned shivering, his flames flickering excitedly. Where Gaster was grinding Grillby's flames started to deepen in color almost sinking into the elemental.

Gaster blushed "oh can you change your parts too?" He cooed

Grillby whined pushing the other away lightly giving a whispered whine of "s-stop."

Gaster stopped immediately smile vanishing "am I bothering you?" He asks worried he was breaking some limit

Grillby worried his lip. He knew he was just being emotional and a baby flame about it, but he was still upset. Grillby's flames crackled loudly compared to his whispered voice "n-no… I-i'm. i just. i'm mad at you… i… i don't want to hurt you… Gaster, you wanted me to use MY flames, my being as-as an experiment. Just the thought..."

Gaster frowned and cupped his face "Grillby... I'm sorry I didn't mean to hurt you I was just excited..." He said

Grillby clenched his jaw, though his face took on more of a sad look than anger. "Excited. Why? Because maybe, on a whim, because we bonded that i wouldn't be able to m-melt your bones or-or turn you to an a-ashy d-dust like-like those meat covered skeletons i-i fight almost e-everyday? Is-is that what excited you? B-because it didn't excite me."

Gaster sighed "yes it did I'm sorry" he said nuzzling him

Grillby sniffled leaning into Gaster heavily "s-sorry… i shouldn't have said that. I know how excited you get when you discover something new. I shouldn't be making this into such a big deal… i-if you really want t-to try l-later w-we c-can."

"No if it makes you that uncomfortable we don't have too" Gaster promised and nuzzled him

Grillby let out a small sigh of relief and gave him a kiss "thank you." promised himself to at least try a small flame for the skeleton later, though there would have to be at least two healers around. Bashfully Grillby told Gaster "we can continue if you want."

"It's not what I want it's what you want" he said and kissed him gently

Grillby hummed into the kiss. wrapping his arms around Gaster he hoisted the up and walked them back to the bed flopping down leaving Gaster on top. His flames had sunk inside of him creating a softly flaming slit. "i want you inside me~"

Gaster smiled "and so I will be... So cute..." He cooed and stroked the slit blushing

Grillby gave a low rumble, almost purr like. He had only summoned these parts once he hadn't realised they were so… sensitive. Gaster's cool bones were like ice.

Gaster slowly began pushing his fingers inside working his lips to loosen him and loving the sounds his lover made.

Grillby groaned at the intrusion his flames sparking excited at the movements Gaster was making

"To each his own..." He said nibbling his neck as he thrusted his fingers harder

Grillby gave a small moan at the hard thrust and rocked into the fingers inside of him.

"I can't wait to be inside you" he purred and inserted another finger

Grillby shivered rocking himself on the fingers giving a needy whine "please Dings."

"Okay..." He said and removed his fingers and moved so his cock was at the entrance he took a steadying breath and began pushing in

Grillby moaned loudly at the feeling his back arching

Gaster moaned above him and slid in easily "you're so hot..."

Grillby moaned his flames quivering "y-you are like ice... so nice..."

"Thanks?" Gaster said but was glad he approved

Grillby nodded moving his hips with a moan.

He began thrusting and kissed him. it was so tight, so unbearably hot, and he loved it.

Grillby moaned into the kiss moving with Gaster's thrust. He wrapped his arms around Gaster pinning him there for the time being.

Gaster purred glad Grillby still had a sense of control. it felt good as he topped him.

Grillby wiggled and rocked with Gaster in an insisting way. Opening his mouth Grillby wiggled his tongue into Gaster's mouth and tangled their tongues.

Gaster moaned at their tangled tongues and began thrusting harder wanting to please him

Grillby lean his head back releasing them from their kiss as he moaning loudly. Grillby looked up to Gaster eyes hazy and drooling slightly.

Gaster licked up his drool "so messy..." He teased loving how undone the normally stern warrior looked

Grillby gave a small whine pulling Gaster's teeth to his flaming neck and licking at the skeletons skull where his ear should be. "Gaster~"

Gaster took the opportunity and bit down on his neck moaning as they became even more bonded

Grillby gave a stuttery moan clutching at Gaster's ribs and skull. "Ga-gaster~"

Gaster purred and removed his teeth "yes my love?" He said licking the lavender bite

Grillby shivered his flames flickering wildly. He tried to focus on the other, but Gaster was making making his mind hazy and a heat bundle inside him. Panting Grillby relaxed heavily into the bed "amazing~"

Gaster loved how the other flared and the hazed look. it was amazing. he thrusted at more angles trying to find the perfect one.

Grillby moaned loudly arching off the bed as Gaster hit a spot inside him that had him seeing stars "Ahh~" the heat knotting inside him getting to be almost painful.

Gaster smirked and began pounding into that spot

Grillby's flames blinked out for a second as he orgasmed. He arched up with a loud moan of his lovers name before flopping back onto the bed spent. Grillby panted drooling onto the blankets looking up at Gaster with hazy tired eyes.

Gaster cried out in pleasure before cumming himself filling his sweet mate with his cool spunk

Grillby groaned as he was filled Gaster's cum cooling his very core. His tongue lolling out as he gave a long moan. Grillby mumbled half praises "so good… love… Gaster… Ahhh good… cool… nice… love."

Gaster purred and licked Grillby's face clean like a sated cat. "You are too good... Love you my perfect flame"

Grillby moaned rumbling and giving half hearted attempts to lick back, but it just ended up with his tongue wiggling and poking towards the other.

Gaster giggle and licked his tongue. "Hehe silly Grillby..." He purred and laid on his strong chest "love you"

Grillby huffed out a hot breath into Gaster's face rumbling sleepily "love ya to Dings."

"Love you too" he said and pulled out laying on him and closing his eyes purring

Grillby gave a soft groan as he pulled out. Nuzzling Gaster he mumbled eyes drifting close "don't leave... Stay with me Dings... I love you..."

"I won't leave... Ever" he promised and he did. fight after fight he waited for his lover to return ready to heal him and any others throughout the war.