Grillby x Gaster [Lemon Oneshots]

~Date Night~

[Jan 2020: It's been a few years guys! If anyone still uses Wattpad and loves them some Undertale, I'm here, I'm queer, and I'm writing some gay fanfiction.]
[WARNING: NSFW]

***

Some time had passed as Gaster and Grillby grew closer and more intimate. Grillby babysat every now and then while Gaster worked on experiments, tinkering with newer and more efficient energy modules. The king and queen, however, seemed to be babysitting more and more as the two monsters wanted time alone in the evening...

Tonight's the night. Grillby had been metaphorically sweating bullets about the events to take place. After a few weeks of catching up, and getting to know their older and more mature selves, they were more than ready for more intimate activities.

[It is well known that monsters are composed of magic. When excited - or whenever they please, they may form organs for sex]

Gaster - the big nerd - had never been in this position before and was a bit afraid of the unknown. However, he has trust in his soon-to-be lover and was more excited than anything to be with his partner.
He had showered and freshened up before dropping off the boys at the Royal Palace. Toriel waved him off, "Have fun at your date night!"
His heart pounds as he walks towards the restaurant, as the sign: Grillby's name, illuminates the snow with an orange glow.
The anxiety within him builds until he opens the door and sees Grillby's face. All the pressure within him fades and he sighs a relaxed breath.
"Ah you're here! I have dinner ready for us!"
Grillby gestures to a candle lit booth with plates and silverware.

[A cute, but nervous candle lit dinner later]

They cuddle watching TV, and digesting their dinner. Sleepy, full-bellied cuddles lead to a power nap...
Gaster's eyes flicker open as he cuddles into Grillby's warm chest. They must've been asleep for an hour or so. He glances down and feels something warm and solid pressed against his leg. 'Ah a nocturnal erection' Gaster thought to himself. He rubs his leg gently against it and Grillby's eyes opened suddenly. He felt incredibly horny, and the urges he'd kept below his polite mild mannered demeanor began to surface with this sudden stimulation. He pushed his lips against Gaster face, kissing aggressively, and grinding his hips, rubbing his erection harder against Gaster's leg. This was the moment he'd been waiting for.
A bright blue blush glowed on the fire elemental's face, contrasting the deep purple color tinting Gaster's cheekbones.
The skeleton had not known what he'd started, but he was eager to find out. A magical purple glow was manifesting within his own trousers as an animal instinct began to take hold. Thoughts of desire, wanting Grillby, wanting to hold him tight, to be closer to him to any other, flooded his mind.
He scooted back over Grillby's waist, unbuckled his belt, and yanked his dress pants down. Rubbing his glowing erection through his briefs, he pressed his face against it. Pulling his briefs down revealed a pulsing, orange-glowing dick.
Gaster took a second to appreciate the vulnerability of his lover... Shirt unbuttoned, cock out, totally disheveled.. and ready for more.
He wrapped his hands around it and put the tip in his mouth. Working the head gently with his tongue [Yes, magic tongue, magic saliva, I know you've seen the DeviantArt], he twirled circles around the top, licking the hole gently. He proceeded to do a lick from the base to the tip while looking up at Grillby. Grillby shuddered and let his eyes roll back a bit.
He sighed deeply and smiled as Gaster began moving his head back and forth, sucking slightly as he pulled away. He'd pause only to suck on the head and stroke the shaft with his right hand, giving his throat a rest. He didn't expect giving head to be such a workout, but his desire kept pushing him back for more. That, and Grillby held his head gently and started thrusting into his mouth.
Grillby sat up on the couch and pushed Gaster down by the shoulders. He pulled down his trousers and briefs and revealed a magic purple erection, sprouting from.. seemingly nowhere, but from his pelvic region. He began to reciprocate, sucking on the tip, licking away some magical violet precum. He breathes heavily next to Gaster's skull, "would you like to 69?" He pants politely.
"Uh, er, Yes. Please."
Grillby removes the remaining clothing from his bottom half and orientates himself above Gaster, with his legs above his partner's shoulders. Grillby begins stroking the shaft while sucking the head and working his tongue around, while Gaster tries to take Grillby's full length to the back of his throat.
Gaster begins to freeze up as the pleasure occupies his mind and nothing else. He feels a pressure building and building until he feels it release. Grillby feels spurts of hot cum hit the back of his throat, feels it fill his mouth with a slight salty, alkaline taste. He swallows, because a spitter is a quitter, apparently. Also he was about to cum and did not want to interrupt his lovers attempts at deep throating. He releases his load into Gaster's mouth, as the skeleton contemplates on the strange new taste.
Grillby turned around and collapsed onto Gaster chest, breathing heavily. They share a passionate kiss where their tongues mingle lazily, and as the kiss breaks Grillby holds his lover close and whispers,
"I love you.."
"I love you too."