Undertale one-shots

One shot-Kustard (Omorashi)

Trigger warning: contains sanscest and omorashi (piss kink)

It was a normal day for Sans. His brother had gone to his daily training with Undyne, leaving Sans alone on his "day off". He was planning on doing nothing, but life threw him a curveball in the form of his boyfriend of three months, Red. He was laying on the couch, asleep (not surprising), when his phone buzzed in his pocket. He pulled it out of his pocket, thinking it was a notification for an app, but sat straight up when he saw it was a text from Red. He quickly opened it, read it and responded, now completely awake.

[A/N: Red's speech and texts will be lowercase and underlined, Sans's will be lowercase, Paps will be UPPERCASE, and Edge's will be UPPERCASE AND UNDERLINED. Notes will be in brackets and texts in the fancy-looking parentheses.]

{sans, i need your help!}

{what's wrong babe?}

{i... i can't get in my house and i need to get in!}

{pfft, really? lol}

{it's not funny sans! i really need to get inside! it's an emergency!}

{why can't you just teleport yourself inside?}

{... you'll see why when you get here. and don't make fun of me!}

{i won't}

{please hurry}

Red's last message worried Sans. Red only said 'please' when he was desperate. He got up, put on his slippers, put on his blue jacket, and teleported to Underfell. He found Red, standing in front of the house that he and his brother, The Great and Terrible Papyrus, shared, bouncing on his heels. [A/N: 🎵bouncing around, bouncing around, bouncing🎵😂]

"red, are you ok?"

Red whirled around to face him, looking a bit nervous as his eyelights scanned over him, like a bar code scanner over a box of gummies.
"uh, yeah, i-i'm fine." Red replied with a slight stutter. Sans could tell that Red wasn't 'all right'. He grabbed his hand and teleported them both into Red's living room, which was empty.

"there, we're inside. now, who's the best boyfriend ever?"

Sans let go of Red's hand as Red let out a soft moan.

"babe, are you sure you're ok?"

Red nodded, his face bright red, like a cherry. Sans looked a bit confused, the cause of the confusion, Red's face or his moan, wasn't 100% clear, but he shrugged it off, walking into the kitchen and finding a bottle of ketchup.

"guess it's my lucky day. did you get this for me?"

Red nodded again, too flustered to speak.

"awww, thanks. i'll get you some mustard the next chance i get, ok?"

The only response he got was a whispered "thanks". Sans thought nothing of it though, and started drinking the ketchup, straight out of the bottle, closing both sockets as he did. Red looked over, made sure Sans wasn't watching, and immediately bolted for the stairs. He got halfway before he froze. Sans had watched him run, and was a little confused as to why he'd stopped.

"red, aren't you gonna go upstairs?"

Red's POV

I froze about half way up the stairs as I started leaking. Then I saw Sans walking over out the corner of my socket.
'Shit, Shit, Shit!'

"red, aren't you gonna go upstairs?"

Then I heard it: the sound of liquid hitting the floor. I started to tear up.
'No, I thought that I could make it! No, No, No!'
I could feel it running down my leg, and it was relieving to let go, so I moaned. I could tell  that my face was a dark red because it felt like it was on fire. I could also feel Sans staring at me. I went about a full minute, and by then, my shorts, sneakers, and socks were ruined. And, I was positive that was my relationship with Sans was ruined too, along with the floor. I looked down at the mess I had made, and started crying.
'No, stop! He already thinks that you're a baby!'
"hey"

I looked up at him, and, in that moment, I saw more love in his sockets than there was in the whole underground.

"hey, don't cry, please. how about this, if we get you and this mess cleaned up fast enough, we can go out for nice cream. do you like that idea?"

I nodded enthusiastically smiling, but then I thought of something.

Sans's POV

He looked so happy when I told him my idea, but then, his face fell.

"babe, what's wrong?"

"d-do you h-hate me?"

"what?! no! i love you, with all my soul. i could never hate you."

He smiled again, as I grabbed his hand.

"now, you go upstairs, take a shower, and change, while i clean this."

He giggled, and said a happy "ok!" as he ran upstairs. I chuckled to myself as I looked for the floor cleaner and the mop.

[A/N: 815 words, not counting this. What do you think? 🤔💭 I'm using way too many emojis. XD Comments are everything! They are my inspiration, the fuel to my fire to type these things, & gives me a glimpse into the minds of viewers! Plus, lots of comments makes me look popular. Something I'll never be! Hahahaha... 👋 BYES!]