Undertale Smut

Sans x US!Papyrus x Reader

(This was a request and I decided to get to this one first. It's probably the easiest so far because honestly I'm not comfortable finishing the Papyrus x Reader and I was requested a Papyrus x Sans x Reader as well so...)

Everything was fine after the monsters returned to the surface. Everyone got used to them and started to like their company. You, oddly enough, had a relationship with one of them. It was odd because he was a skeleton and you were a human. But you loved him and he loved you back.

But something odd happened.

Another timeline of monsters made their way to the surface as well. This time, everyone was... swapped. Their personalities were changed to the opposite of each monster. It was strange having another set of monsters on the surface, but you lived with it. They were new, and you found them okay as well.

One of them was Papyrus with the personality of your boyfriend, Sans. It was weird seeing Papyrus like that, being the pun-hating goofy skeleton he was. You became friends, but Sans seemed a little bit jealous.

He didn't want Papyrus to replace him. Not on his watch. So he decided to let you do something a little bit different.

One day Sans invited you over to his and Papyrus' house. He invited the swapped Papyrus as well.

It was weird because the regular Papyrus wasn't home, and he would be the one greeting you at the door, but it was Sans this time. You and the swapped Papyrus arrived at the same time, and it was kind of awkward. "Oh, Papyrus, Sans invited you too?" you asked curiously.

"He did. I don't know what for, but it may be kind of important." Papyrus responded right before Sans opened the door. "Hello guys, come on in." He grabbed the two of you and teleported you into his room along with Papyrus. "(Y/N), I have something to ask you." Sans paused for a minute. "Are you cheating on me?"

"No, I'm just friends with him!" You responded in a worried tone. You never knew Sans would ask this, and you were kind of worried that your boyfriend would break up with you.

"Well, if that's the case, I wanted to ask you something." Sans stood up and his left eye glowed blue. "Would you two like to help me with something fun?"

You knew what Sans meant by this. You blushed deeply. "Papyrus, what do you think?" Papyrus immediately blushed a bright orange. "Oh, shit, uhh..." He paused for a minute, sighed, and answered. "I will."

"Well then, (Y/N), bend over for me." Before you did that, you undressed. Papyrus' blush was even more orange. You finally bent over while Sans took off his pants to expose a glowing blue ghost cock. "Ohh shit..." You knew Papyrus was already turned on because his pants were glowing orange where his crotch is. He sighed and took off his pants.

"Well, let's begin!" Sans finally thrust into you. You yelped. You didn't expect it to feel this good...

You were already soaking wet and so hot in your crotch. You decided to help Papyrus out a bit. You rubbed his cock and then stuck it in your mouth and sucked. The amount of pleasure was overwhelming you, and you couldn't hold it in anymore. You knew you just started, but you were moaning in Papyrus' cock.

"Oh God, this is so good, I think I'm gonna..." Papyrus couldn't even finish his sentence before he burst out into a series of moans. Sans wasn't that far either. "I'm cumming, ahh shit... Nghh!" Sans' cum covered your inner walls as your walls clenched around him. That was all it took for him to spill his seed inside of you.

Papyrus followed right after. He leaned his head back and let out a loud moan as his cum shot inside your throat. He pulled out of you as you held his cum in your mouth.

"Oh uh, you can spit if you..." You cut Papyrus off as you swallowed his cum. After that, you dozed off along with Sans and Papyrus. You had fun, and so did the others.

(SLAY ME)