Underswap Sans x Reader Smut

First Time for Everything

Your P.O.V.

It was Friday afternoon and you thought about the week that you had. Alphys was teaching you to fight and beat you up pretty bad in the process. She was very violent. Of course papyrus laughed when you got thrown to the ground. He didn't really think much of you (except when you were in the bedroom). Sans on the other hand went to your side and asked if you were okay. You smiled at him and told him that you were fine. After that you spent the rest of your days at home watching a Napstaton marathon with Sans. Papyrus was no where to be found during those days but that was just typical Papyrus. He would just miraculously show up on Friday like always.

It started to get late and there was still no sign of Papyrus. You were home alone since Sans was over at Undyne's lab. You decided to turn on the T.V. and watch a couple of Napstaton's music videos. They were always playing on the same channel so that people could watch on the T.V. if they wanted to instead of on the Undernet. A few music videos went by but still nothing.

He's probably at Muffet's getting drunk, you thought. You got up off of the couch and were about to go check when Sans burst through the door.

"HUMAN!" Sans was doubled over and out of breath. You looked at him quizzically.

"Is everything alright?" you asked Sans. He held up a his pointer finger as if to say, "One moment please"

"huff....huff.....I got here as soon as I could."

"Why, what's going on?" you asked. You were starting to get a little worried. Sans regained his breath and stood up straight.

"Papyrus is spending the night at Undyne's with her and Alphys so I got here as soon as I could so you wouldn't be lonely!" Of course he is... you thought. Sometimes he would stay over at Undyne's without warning when he didn't want to do anything with you instead of just telling you. Most of the time when he was there he would either watch anime with them or have threesomes with them. Mostly when he was just bored of you. Usually, Alphys would take Sans to her house so he could spend the night there while she was with Undyne and Papayrus. But this time something was different.

"Thanks Sans." You said to him with a warm smile. He was just so innocent and really cute to be honest.

"Your welcome human! The Magnificent Sans is here for you!" You smiled once again as you sat on the couch with Sans sitting next to you. Usually on Friday nights without Sans and Papyrus you would watch a whole lotta porn. But with Sans sitting so close to you, you weren't able to do that. So, you started to watch more music videos with Sans. It kinda felt awkward.

After a few more videos, Sans broke the silence. "What do you and Papyrus do when I'm over at Undyne's?" He asked. Your eyes widened and your face started to turn red.

"Uh....nothing..." you replied. You hoped that he would drop the subject but of course he didn't.

"That's not true! I saw you walk out of Papyrus' room last Saturday morning!" Shit, you thought, how am I supposed to make up an excuse for that?

"I can't tell you."

"Why not!"

"Because....I just can't!" Sans huffed and looked slightly angrily at you. Then, suddenly, his eyes widened. He looked at you and you could tell that this wasn't going to end well. He proceeded to taking your hand and swiftly leading you up the stairs, past Papyrus' room and straight to his. He led you in and closed the door behind you. You've actually never been in Sans' room before but you could tell that it was much cleaner than Papyrus' room. You were nervous about what was about to happen next.