Grillby x Gaster [Lemon Oneshots]

~Closer~

[Aug 2021: Hey guys! It's been another year and I've been enjoying some slash fics, so I thought I'd add a real spicy chapter to this fic! I'm sure no one's gonna read this after so long tho 😅]
[NSFW]

***

It was late. Very late.
The boys were fast asleep, and the distant hum of the TV provided a comforting white-noise. It didn't matter what was playing, no one was paying any attention.

Blocking the glow of the TV was the silhouettes of one skeleton and fire elemental making out passionately on the couch.

After the previous night, they were getting quite comfortable with being physically and emotionally vulnerable with each other.

Gaster grabbed at Grillby's shirt with one hand pulling him closer, and held the back of his head with the other. Locks of harmless flame flickered between Gaster's boney fingers.

Grillby had other ideas...
He began quickly unbuttoning his shirt and tossing it to the side, unveiling the warm glow of his toned chest.

Gaster's erection became uncomfortably tight in his pants. He started unzipping and sliding them off. Grillby's attention focused to freeing Gaster from the remainder of his clothes.

Gaster's purple glowing cock [isn't magic wonderful..] springs up as Grillby removes his briefs. The fire elemental then crushes his mouth to the skeleton's, working his tongue inside a little forcefully.
At the same time, they grind up against each other, eager for more stimulation.

Grillby pulls away reluctantly, but asks permission for what he so desperately craves. "C-can I fuck you? Please?" He pants, and blushes blue. Gaster turns as violet as his throbbing cock, but responds, "Yes! Please! I'm ready. I-i want you inside me."

Grillby quickly removes his own pants, and lays Gaster down on the couch. He bends down and licks the tip gently. Gaster shudders and thrusts slightly into Grillby's mouth.

Grillby begins sucking, stimulating the tip and shaft with his tongue while working up and down. He wets one of his fingers with Gaster's slippery pre-cum, and glides it around the rim of a magically conjured anus.

He makes a few little circles around the rim, and then slowly slides a finger in. Gaster lets out a small moan, but relaxes as Grillby continues sliding his finger in and out.

Once adjusted to the width of one finger, Grillby adds another, and then another. Gaster is a purple flushed mess at the point, eyes glassy with desire, pre-cum dripping from his tip.

Gaster decides that he's probably well adjusted enough to take Grillby's full length and girth. He spreads his legs a little further to make it clear, "Grillby.. Please, I want you so bad!" "You're so fucking sexy when you're a mess like this"

Grillby positions himself on his knees on the couch, and guides his own cock towards Gaster's slick and eager asshole.

The tip slides in.

Grillby grasps hold of his Gaster's pelvis, "It's tight, really tight."
Gaster worries he may have underestimated his lovers girth, but Grillby pauses for a moment to kiss him, and he begins to relax.

Grillby slides in further - deep inside Gaster's warm tight walls. The feeling of being filled up like this was totally new to Gaster, the pleasure and excitement washed over him.

The magical warmth, slickness, and pressure was driving Grillby mad with desire. He began slowly picking up speed, thrusting faster and faster.

He grabbed hold of Gaster's hands and held them against the couch above the skeleton's head. As he pinned him down, he thrusted with more force and passion. He moaned deep and low, "Uh, you feel so So good.. fuck." He kissed up his neck to his jawbone, then found his mouth.

Gaster's thoughts were disconnected pieces of desire: "hn, deeper... faster... harder!" He wrapped his legs around Grillby's torso, pulling him in as deep as he could go.

Grillby could see they were both getting close, so he worked Gaster's shaft while thrusting into him.
"oh Fuck, uh..." He moaned - trying to keep his voice down while doing so - he thrusted deep inside a final time where he twitched and released several pumps of thick cum.

At the same time, Gaster bit back a moan with his hand as he twitched and came, jets of purple cum landed on his ribcage.

They both sat there panting, exhausted, but admiring each other.
Grillby's face burned bright blue as Gaster gathered his thoughts:

"Next time.. it's my turn to be on top. 😏"